If you saw those latest NVIDIA drivers that mentioned Gears of War, well, according to Epic's Mark Rein it's much ado about nothing (thanks BU):
"There is no "new information" that Gears will be released on PC. You know console games are developed on PCs, right? Even if we never release Gears of War on PC we still need to run the game on PC to develop and test content for it
Our first E3 demo, over two years ago, was done on an PC equipped with dual NVIDIA graphics cards. That was how we simulated the power of Xbox 360 before there was actually a real Xbox 360 to run on..."