@AndyC: I agree that a real roaming profile would be rubbish.  But it seems to me that is what is being proposed in all but name.  Synchronization of settings: i.e. Favorites, Feeds, Application Settings, and remapping the documents to a skydrive folder isn't that far fetched.  Do I like the idea? Nope.  Not so much for the data corruption issues, as so much as I like local storage.  Until Windows 8 comes out, we really have no idea what they really mean by cloud.  We could be looking at something similar to Apple's MobileMe in the end.