It's the sort of thing that you think could be cool, but when you start to play out what that would mean from a development perspective, splitting the development effort to make a single-player campaign and a multiplayer mode would have ended up with us making two pretty average games.
Our focus is on delivering an off the scale, awesome Batman experience, and that experience is fundamentally a single-player experience. We did consider it but when we thought it through from a production perspective, we thought it would compromise the end result.
OK, OK, so Batman multiplayer probably wouldn't have worked as well in Arkham City as it does in our dreams. Ginn goes on to comment that multiplayer modes are a strong trend but that they can feel "bolted on" when developed for the wrong games.