[ericd]

Don't forget the friends list, in-game/cross-game chat, and growl-style notifications when your friends start playing something so you can hop in a game with them. All those other things you mentioned are huge as well, and I just don't see Microsoft replicating all of these things well. Cross platform is also nice, where applicable. Having to be online and have steam running before playing is the only major complaint I have.

[desas]

They have already implemented all of those things for the xbox, it can't be that difficult.

[fsaintjacques]

Have you ever played a game with Windows Live on PC?