I'm in the audience of Microsoft's Partner Preview for Computex 2011, basically an event to give a sneak peak of the future of Windows to press and MS partners here in Taipei.
Of course I'm talking about Windows 8. On stage there are several systems running a wide variety of hardware. Microsoft has machines from AMD, Intel, NVIDIA (presumably a Tegra 2 or Kal-El notebook?), Qualcomm and Texas Instruments. That's five players when Windows 7 really only launched on platforms from two different silicon vendors.
Here's a quick look at the new start screen for Windows 8 running on a Dell XPS Development Tablet. The tablet supports both touch and external keyboard interfaces. The UI is ridiculously smooth, it seems even quicker than Windows Phone 7.

On tablets Windows 8 will support PlayBook like bezel gestures (the gestures actually take place on the first pixel next to the bezel, apparently not in the bezel itself). Gestures for the OS take place on the left/right edges of the screen, while app gestures happen on the top/bottom bezel.