This interface is so bizarre in comparison from what I use on the mac currently, that I can only look at this as a whole new design, instead of an improved or new design.
I am going to add some notes and my two cents on it though, looking at the PC app from the Mac lens. Though hopefully, they'll get all the glitches and odd ball things worked out of the design before they build the Mac version; I'll have to see if my Mac version is the most up to date Skype app.
Would love to see a roast comparing the platform differences on this app between Mac & PC.

Never been a fan of this mottled glass look for the new PCs, and I am only pointing it out now cause it doesn't do this layout much credit. I should point out that the Mac app interface looks totally different; a comparison roast could be fun :)
This one in particular looks more like a single person that's kinda of splitting ..... or exploding. Would have liked to see the typical [single person] and plus [+] symbol to bring some levity and eye direction to this toggle.
Would have been fun to see some more creative buttons. Looks like its a run of the mill css. Could have had fun with shapes and depth styling these.
on the mac, there are nice solid background colors when the speakers change, and clean HR rules between posts; this was not a good thing to remove. Definitely needs something here to more clearly state when speakers have passed the mic.
This seems very floaty. Could have been much better with the width expanded, and more space below the window. What happened to that slider bar that allows you to expand this type box or elongate the conversation view?? I am constantly using that! - Ha, never-mind. I guess its that dot above. Not cool; gimme my bar back!
Is it really necessary to put all of the icons for INSIDE the skype icon?
This seems like something that should be on the top, perhaps paired with the friend search tool bar.
This looks like if I click it, it would expand and show a new left pane with call numbers... but is it just a button? The icons aren't consistent at all across things.... makes it hard to stereotype the apps functionality.
This would be nice to see with the "search for people" feature... seems like they would be a good pair
This looks like an expansion window, like an accoridan, that when clicked will slide up and give me call options in the left hand menu, but since this looks - in particular the icon - looks little like the icon on the other silver bar at the top, not so sure. Consistency would be much welcomed, especially in the icons used.
Are these icons gray because you've hidden this info? If not, seems silly to have one colored icon (the flag) and gray out the rest.
I use Skype on the Mac quite a bit and, as a program on the Mac, it has a very small footprint. It's more of an IM client than a full blown app. Not sure I have seen the Windows version prior to this one so I can't really say if this is an improvement for Windows users. But this feels like a beta interface to me. Maybe this is function of this app maturing from more of an IM-type utility to a full blown desktop app. I have to say, overall it looks like it was on it's way to becoming something really nice and got released before it had been put together and polished.
Where the experience falls apart for me is the transition from tab to tab and when you jump into the "Account" section. Since I am only getting the experience from screenshots I can't say for certain if this user experience is as divergent as it looks, but I feel like there are several different design teams working on different parts, not caring what the other is doing. There are several different backgrounds, no consistent look to the icons, a form that looks like you are on the Skype website, 2 different phone keypads, etc. Most of my critique will be in the notes but overall I have to say that this interface needs some polish. If you are going to make this big of a leap in changing your software I feel you need to do it right. I just don't think it was "ready for primetime" from a user interface design standpoint. But the software works well and at the end of the day that is what people want it to do. Good UI is just a bonus when you get it.

These status icons are supposed to be functional and I feel they fall short because the designer wanted to be cute and make it more "artsy".
Grey icons mean "disabled". Not a good use if these fields are just providing information.
This look has kind of come and gone. Plus the green is not in line with the rest of the interface pallet. Plus, why are they so crammed in here? They need some room to breathe!
Many IM programs will move all "online" to the top, then "away" and finally "offline". Again, a fairly common practice not followed for some reason.

There is no consistency in the look of the buttons throughout the UI.

It looks like the account section, but that also feels so different from the rest of the UI.
Not sure why you would place a button that opens another "tab" on the right hand panel here? It just feels out of place.
This is a big no-no in UI design. A user could get very confused when their main tabs just disappear like that.

This screen looks SO out of place, but since I don't use the Windows version of this software I don't know the context of it.

Why does this function need to be in a pop-up? And why does it look like the website and not like the rest of the software?
The bottom line says it all: Design it as one app with one concept for layout and visuals´.
The most obvious thing is that this version is clearly not one app and has no overall concept.
There are currently different interfaces with a completely different style, layout, color scheme and (it seems) target group.
It seems partly focused on the social networking crowd with facebook like visual clutter, but the sound test service is extremely clean, while the add a contact screen is very friendly childish in its presentation with a very basic underlying form script.
You would expect the two payment modules to have a look similar to at least one of the other screens but no, they seem to stem from yet another lay-out guy who just dressed up a form without any style resemblance to the rest of the site.
I think this is a major error as people don´t want to pay on a screen which looks like it´s independent of the site. It suggest that you´re are redirected to a completely dfferent site so people will hesitate to make a payment. The largest flaw as this is the core of the Skype business model.
Let´s analyze the target groups as far as I know:
youngsters coming from the facebook, twitter, social networking area where making phone calls (for the younger readers: with actual phones over land lines or the not be trusted mobiles ;) is rare
elderly who keep in touch with family living abroad or while on holiday who don´t know anything about technology, don´t know that they are now using VOIP and still wonder how their nephew got a photo into their cheap phone program.
Of course there is a middle ground as well but the large in between age group doesn´t want to be bothered by phoning from a computer, can afford the charges and are used to it, prefer the know quality of non VOIP calls and know how to use the handy services which let you call in to a local number abroad and use their mobile to get through to phone in a different country. Usually no skype users but occasional users of other cheap international services or people who just buy a local sim card to avoid roaming.
From a marketing point of view the problem created by all these different screens, concepts and layouts is that as a program it ends up targeting nobody. The fluffy Add a contact screen will feel comfortable for the older generation. The facebook like chat windows looks already outdated but will ´good enough´ for the avatar generation and the sound test page would be comfortable for the middle aged business men who just like functionality.
As a total however it distracts and even alienates the existing two user groups and it will certainly not attract the financially very interesting group of middle aged professionals.
No need to go into the details of the screens: this is not even an half hearted attempt to integrate functionalities and a failed attempt to broaden their appeal.
This is reflected in my scores where I cynically give three stars for originality as it would be hard to make a briefing that results in this incoherent app.
I always liked their design. The little changes they made don't go over-board and keep functionality untouched. Skype and YM are handy well-designed tools.
Well-used color scheme. The contrast is just right. Great whitespace management.
The base line is that I never got lost in their interface when using it. Never bothered me and that's the whole point.
Skype have become the part of our life... be it computer or mobile. Skype is a Global brand in VOIP industry, however, there are few things which I think can make it more aesthetic and pleasing.
I have attached my notes which I hope will help.
Thanks, Haider

I think... it's really no use of showing the thumbnails here, thumbnails only increasing the height of the all contacts section and user can't see the maximum number of contact and ultimately compelled to use the scroll bar. I think earlier version was finest in case of the all contact listing view.
I think here it's not pretty noticeable as it was in earlier version, from the top it's easy to find the add a contact
Message field size doesn't increase horizontally when you are increase the window size
I think taking off this default window and adding some of it's own default design could do magic
“n” number of icons with different size isn’t aesthetic Mobile tab have a small icon of mobile whereas Skype tab have a big (comparing to the other icon size i.e. mobile and add to phone number tab) Skype" icon in blue (In case of the selected tab) but if we click on mobile link, it change the background of the tab to white, whereas, I think it should change the color of the icon as well. When Mobile tab active Skype icon should also be in grey shade as the interaction works with the rest of tabs
add people = add people to join the conversation. I think copy of the add people may be more interactive and purposeful
separator padding/spacing for each tab have a difference of 3 pixel in RHS


Lense, recent, all contacts, close and home...

I think centralized design with the window might look better
Please keep in mind this is an outsider looking in review as I haven't used Skype in while... this is based on what I remember when I did use and the above screen grabs.
I have to agree with Catalin mostly.
The interface is very well designed and has always been user friendly and easy to navigate. They use modern graphics with icons that allow for better ease of use and navigation.
However, the UI in different areas / functions vary. Talking about the call UI vs the add contact UI. I think they should make these more in sync with the main branding style of the main app interface.
I think from a tools perspective it would make sense for them adapt project sharing tools like base camp has.
It would be nice, if you had a botton, so you could switch between a horisontal and vertical view.
The horizontal view is for mobile phones, tablets, etc.
It's a long time since I used to say that Skype is the best application I ever used.
It's very stable, clean and definitely very very user friendly.
Hey Skype, I give you five :)
Stay free!
I am on Skype everyday and the existing application is rather easy to use. The new application design makes contact information easier to see and find. I like the new application not sure I want my Facebook info on it though due to security issues. So I do hope that is an option.
I really like skype design, as Curtis Scott said it works, and thats true!
Maybe they could work some more on the contact display screen, add some quick call icon.
But theres not much to be changed, it works and its simple.
it looks like...but my first impressions were that skype was trying to copy a Mac UI design with the boring layout and poor interface design of windows.
I'm not so familar with Skype but I think its a nice cool style, however a switch between horizontal and vertical would help as one other reviewer suggested. More and more computers exploit widescreen views especially the newer Macs and straight down pages are becoming a somewhat tired concept from 800x600 days. The contacts in the left hand panel would be much better if highlighted alternately, perhaps in the same gray used on the tabs.
I'm a regular skype user on Windows. I like the mac version and have found it very intuitive. The windows one is a bit lacking in terms of usability and design.
I concur on most of the other reviews.
I got couple of observations to make:
I think the overall UI, the form/button styles, use of icons, type, etc. lacks consistency.
Whenever I install skype on any of my systems, the first thing I do is View -> Compact View :) More on that in the image note.

One click Show/Hide button to switch between the compact view and detailed/default view would be great! The 2 separate views don't serve any purpose other than the panels being floated in compact view. Having one homogeneous UI can work wonders.
I agree with all your comments!