Completely unrelated, but if the article didn't overwhelm you, the linked video session really is worth checking out. http://channel9.msdn.com/Events/BUILD/BUILD2011/BPS-1004 It shows just how much attention to detail Microsoft has put into the UX design of Metro and Windows 8. Can't wait to see the finished product.
The design aside (which is an entire topic on its own), some of the functionality decisions like contracts just make you wonder why the sodding hell didn't we have these sooner. I mean there's the half-baked drag and drop handler than no one actually bothers to implement even when it makes absolute sense to do so, and that's it. Being able to pull things out of a web service from the file picker, on the other hand, just makes me go "I want this yesterday."