GOW is for PC and next-gen consoles and UE3 based games are being made for PC and next-gen consoles.
EDIT: Let's QFT.
This third-person shooter will be available on the Xbox 360 and the PC. We were told by Peter Moore that Gears of War is currently running at 80% of the visual bar that Epic believes it can achieve on 360. It will also include online play, and should be available after the holiday season.