Part of an interview Sith Gamer had with Robbie Bach that was posted today:
http://sithgamer.wordpress.com/2008/01/25/interview-with-robbie-bach/
SG: One thing you talked about are the games- so far I think the 2008 year seems to be lacking. Especially when put up against the PS3 or Wii.
RB: Well were saving a lot of stuff for GDC, which is where we plan on showing off some big titles such as Halo Wars and Alan Wake.
SG: Any titles we haven’t heard about?
RB: Obviously there are going to be a couple spectacular things going on at GDC.