Absurdist zombie action game Dead Rising 2 (and the alt-reality special edition Dead Rising 2: Off The Record) will today switch over to Steamworks. Formerly attached to Games for Windows Live—or 'the wailing harbinger of misery and disappointment'—the Steamworks versions will offer achievements, cloud saving and all the other Steam stuff.
Owners with either a Steam copy of the game or a boxed retail copy will be able to upgrade, but those who purchased through the Games for Windows Marketplace will not. That said, both games will still function with GfWL—at least, as much as any game can "function" with GfWL.
Perhaps the biggest blow is that Marketplace DLC won't be transferred. "DLC content purchased directly from Microsoft’s GFWL Marketplace store will not carry over to Steam due to the lack of CD/activation key," writes Capcom's blog post. "Those who wish to play the game with their DLC can continue to do so with the GFWL version of the game installation and under the GFWL service."
Head over to the Capcom announcement post to learn the exact minutiae, and for details on transferring saves between versions.