The latest EGM has a rather juicy rumor. Seems that Cliff and the guys at Epic are already hard at work on Gears of War 3 for the Xbox 360. Word is there are plenty of tweaks in the works to the engine and a new 5 player co-op experience. If true, Microsoft has at least another sure fire hit for next fall.
[edited] news post editing, it's actually fall 2010.