New Jet Set Radio (yeah, right)
Fire Pro (even LESS likely)
A GTA ripoff game that doesn't suck and takes advantage of the 360's power. Saint's Row? I doubt it, but we'll see.
Next-gen
Mortal Kombat (doubtful since Armageddon is their focus right now...a 360 follow-up to the surprisingly awesome Shaolin Monks would be cool though)
Next Gen
Guitar Hero - ok, no chance in hell of that happening, but they could just swipe the concept and take a shot at making a better game. Just throw in deeper multiplayer and XBL downloadable tracks (from well-known bands, not just independent stuff) for a decent price and it would be huge. Oh, and get it out before GH II hits.
And I'd think they would almost HAVE to at least have a teaser for Halo 3 to combat all the PS3 and Rev hype, even if it's only 15 seconds long or something.
I'm a tad concerned that they may focus a little too much on upcoming classic games and features for XBL, as if they're trying to steal Nintendo's thunder, rather than focus on what matters more - games for the system. I don't care about a

ing video-chat camera or Street Fighter II online for the 10th time more than I care about Huxley or Too Human info, thanks.
Honestly, even if they DO show Halo 3 I think Sony and Nintendo will own this show just due to anticipation factor alone. Then we'll all be treated to retards yelling about how "WHOO M$ GOT PWNT, 360 IS DEAD, MAKE WAY FOR THA NEW SHIZ." They will inform us how remote controls and mysterious Blu-Ray discs will suddenly become catalysts to overhaul the entire industry. For the better, of course.