Last week, Microsoft confirmed it would be removing the option to buy PC games via Xbox.com as part of the next Xbox 360 firmware update. As a result, Warner Bros. has revealed achievements and multiplayer for the PC version of Batman: Arkham Origins will use Valve's Steam platform as opposed to Microsoft's Games for Windows Live service — a first for the Arkham series.
There's no mention as to whether the game will make use of Steam's other features, like the addicting trading card system or Big Picture mode.
Arkham Origins is due out for PS3, Xbox 360, Wii U, and PC this October. It's the first game in the Arkham series not to be developed by Rocksteady; instead, Warner Bros. Montreal has taken over development with Splash Damage (Brink) handling the game's multiplayer.
As for Microsoft and Games for Windows Live, you will no longer be able to purchase PC games via Xbox.com beginning August 22.
[Gamespot]