It has been reported that Modern Warfare 3 will have Steamworks support. Steamworks is a program that allows integration of all aspects of steam into a game including multi player, game matchmaking and valve game security support. This is the complete opposite of EA’s Battlefield 3 which you may know will not be sold on Steam or have any Steam support.
Apparently, Modern Warfare 3 will be shipped with dedicated server support but there has been no clarification from Activision as for what this actually means for gamers. Modern Warfare doesn’t arrive until November the 8th but you can still pre-order your copy from Steam now from here.