Looks awesome. Just what a tablet OS needs to be.
Did you ever consider that because the Windows Phone 7 OS is actually very nicely designed, Microsoft decided to take it further?
I love tiles on my phone and I can imagine they will work even better on a tablet with more space to play with. The way they've allowed apps to share screen space is also a very nice touch.
I guess you must be pretty satisfied with rows of tiny static icons and single, process interrupting...