Over the weekend I was playing Gears of War for Windows (which releases next week) and I noticed that there are a few new Games for Windows only Gamer Pictures available, so I took this screenshot from the Guide while playing Gears. You can see there are 13 exclusive pictures you can choose from after you install the game. I have no idea why they did not include any new Gears pictures. Seems like that would make more sense, right?
In case you were curious as to where I got my latest Gamer picture, there is your answer.