For all the sniping and insults thrown back and forth between console and PC gamers, we haven't had much opportunity to face off on the same battlefield. Microsoft is rumored to have experimented with cross-platform multiplayer only to cancel the project after PC gamers armed with keyboards and mice dominated their console counterparts. However, Shacknews is reporting that Valve's upcoming Portal sequel will support cross-platform multiplayer between the PC and PlayStation 3.
Portal 2's multiplayer component appears to be cooperative rather than adversarial, so everyone will have to get along. Interesting, users of the PlayStation 3 version will be able to sign into their Steam accounts and access their friends lists. Anyone who purchases Portal 2 for the PS3 will also receive a SteamPlay license for the PC and Mac versions of the game.
According to Gamasutra, Portal 2's Xbox 360 release will lack cross-platform play and Steam functionality. PlayStation 3 users will only get a SteamPlay license for the game after linking their console accounts with Steam. Since Steam functionality isn't built into the Xbox 360 version, those folks may be out of luck on the SteamPlay front, as well.