It looks as though the "libraries" function is a showstopper, no corporate will want to go through all that hassle. The user education factor alone is a showstopper for corporates.
From my preliminary look at Windows 7, it seems to be similar to Vista, except that it crashes apps like explorer.exe far more easily.
If this is RC, God help us! It looks as though we are going to have to wait until SP2 for anything that works.
Ref my last comment - adding a networked drive to the library takes so long, users will think it has crashed. Definitely NOT for corporate users and I can't see home users being impressed either.