I've done some searching and there doesn't appear to be a method of migrating old 2003 based profiles to the new "V2" profiles automatically. Specifically, we're interested in retaining the <Profile>.NK2 file in Outlook, the Favorites folder, and the Signatures folder.
I'm in the process of writing a fairly complicated migration script that'll be executed at login, but seems like this is something that I shouldn't have to do.
The User Migration Tool appears to only work for Vista, not 2008 R2. Any other ideas?