Little that's been announced makes this new version sound like anything other than a PC exclusive, at least for the time being. Consider the new ingredients. You have a boss battle previously developed for the Xbox 360 version (which blew away those lucky enough to see an early version at Epic years ago) but then dropped. You have an editing suite that opens both assets and engine up to a loyal modding community.
And you have an overall effort to make Gears of War not just a swanky port, but a game at home on PC, even though its ideal setup conforms more to the big-screen-and-sofa model than the traditional desktop.