Crunchgear has the scoop of many screenshots of current internal build of WIndows 7.
I won't go into the argument if the UI is beautiful or not and if it is better than Mac OS X UI. What I Wanted to talk about is a new concept in UI we can see repeating in most of the screen shots - The Wheel.
In a lot of the screen shots you can see a new way for the user to choose which application to launch or what option to choose. It's a wheel that you can spin and choose something from it.
What's interesting is that last week I was in a showcase of Microsoft Research labs, and I saw the exact same concept in a demo of next generation tablet PC.
The idea behind the wheel is that drop down lists, one of the more common UI elements today, are very hard to use when your device is a pen and not a mouse. It's very hard to scroll them and choose the exact option. It even get worse when you go to interfaces control by hands (like MS surface) and you need to select a small font option with a chubby finger.
Another problem is that you can't see all of the option very easily.
On the other hand, the wheel lets you see everything with beautiful images. You can easily do a circle notion with a pen or your hand to move it. In the demo I saw you, the wheel also remembered quick motions you did to choose specific options, to make your selection even faster the next time you use it.
So is the wheel going to be the next UI choice? Does this mean that Microsoft bets that in 3 - 5 years we will use pens and our hands much more on many more devices as a way to control applications?