'E' for some 'I want to create something new. Unreal Tournament When we finished I wanted to make a new game. It' only a matter of opportunity and arrange ideas. Our efforts are concentrated all on Gears of War at the time, but in the near future we will see how things go. " So said Cliff Bleszinski, Epic Games design boss, talking with industrygamers.com site.

In short, Bleszinski had that desire to create a new project, you could already guess from the collaboration offered by Epic Games for Bulletstorm.
Gears of War 3 coming September 20th, for now we just have to wait to find out if the game designer has something new in mind.