Username or EmailPassword
Hmmm, doesn't sound good to me. One would think it would work like WP7, put in your email address and password and POOF! account setup done and syncing. WP7 even pulled in my personal email account hosted by the small web hosting service I use.
Maybe it's just one of those billion things that will be fixed before launch. I remember getting frustrated over and over with the Windows 7 Preview before I chilled and realized that even as broken as it was, it was still more stable than Vista. I'm bound to repeat that experience with this one.