Interesting look at the new touch-based (but still works great with mouse and keyboard apparently) UI on Windows 8: Previewing 'Windows 8.
The fundamental issue however is no one wants to use touch as the main input to a computer. Honestly, it's a great demo, but after spending 5 minutes installing some updates and changing the security software on a touch screen computer mounted on the wall my arm was sore and the experience was infuriating. Really, no one wants this, and the people who have are either a) dumb executives who see the iPhone and iPad and say "that's awesome, we want that on everything and b) people who have the need for cool demos or have one of the few apps that would be good on it (ie: Google Earth). Tweeting out "that's awesome" with a touch screen computer is fine, tweeting out lots of things from it, probably not so much.
Also changing the UI of windows to look and act more like an iPad is a great response to the iPad and other tablets, but your PC is not an iPad. Why do people not seem to understand that the two different environments are fundamentally different and don't need to be copied back and forth.
</rant>
Gruber has more as always, put far more elegantly than I :)