Apparently, MS is going to have more AAA games at launch than this entire generation... I guess I'm the only one that thinks that's a little far fetched.
If they can pull it off though, they'll be off to a great start next gen.
Realistically I think we'll see Perfect Dark, PGR3, and Amped 3 from MS along with a smattering of third-party stuff at launch; two or three games from EA (Modern Combat mabye), MotoGP3, and a few others we haven't heard of yet.
Having an RPG at launch would be great, but I don't think there's any way Oblivion or Bioware's game will be done in time.
Picture Half Life 2 characters, environments, and textures with around 100 to 200 characters on screen @ once in 720p. This will give you a very good idea of what Xbox2 graphics are like.