Activision has confirmed that Modern Warfare 3 will make full use of Steamworks for the game's multiplayer mode. Ditching the proprietary system previously used in Modern Warfare 2, MW3 will offer auto-updates for patches, achievements and dedicated servers for the PC version of the game.
The Steamworks integration will be built into both retail and digitally sold copies of Modern Warfare 3, and is currently available for pre-purchase on Steam. There's little incentive to pick up the game right now, so it remains to be seen if Activision will pull a Deus Ex with the title by offering hats and other goodies in Team Fortress 2.