1 vs 100 will be coming this spring 2009.
1 vs 100 is Xbox Live adaptation of the game show. The players are represented by Xbox Live Avatars. The game was due to be released with the "New Xbox Experience" update but it, along with the rest of the Primetime content, was delayed.
Halo Wars Demo Coming Feb 5th 2008 (Someday as Killzone 2 Demo):
Halo Wars is an upcoming real-time strategy video game that is set in the Halo universe. The game is being designed by Ensemble Studios for the Xbox 360. It is the last project to be developed by Ensemble Studios. Halo Wars has been rated T for Teen by the ESRB.