Well I had heard plenty of rumors about some sort of multiplayer in Batman: Arkham City but it seems that was false. No co op no competitive just you and your bat gadgets alone in the city.The Director of the Batman: Arkham City had this to say. “With the game now coming to the final stages, I can honestly say it would not have been possible to deliver Arkham City the way we wanted to if we’d have added multiplayer.”
It kinda of sucks I was hoping to get a co op experience in Batman: Arkham City but it seems that the bat will role alone again. Of course they did just announce Catwoman would be in the game so she might help you out in some spots only to betray you late.
Expect Batman: Arkham City to launch in late 2011.