The tile interface is definitely a shell, right now. It's a stepping stone for Microsoft to step into a post-desktop world. I've read a lot of commentary that

The tile interface is definitely a shell, right now. It's a stepping stone for Microsoft to step into a post-desktop world. I've read a lot of commentary that is very impressed with the tiles and just as much commentary writing it off as something that's not enough and not appropriate for Microsoft to make a step and just put a new pretty face on Windows. To me, I see it as a thought out stepping stone to reaching the post-desktop era that reaches a pretty good compromise. I don't think many people have to be worried about this new transition, but that's my own speculation - you'd have to wait for MS's official word.