Warner Bros. Interactive has just announced a new game using the Batman licence called Gotham City Imposters - it will be a downloadable title (PSN, XBLA and PC).
The game will be developed by Monolith Studios, who're known for the F.E.A.R. franchise, because it'll be a multiplayer 4 vs 4 shooter. However, you don't play as Batman or the Joker. Instead, you play as a member of Team Bats or Team Jokers.
Your character will be highly customisable and there will be adjustable loadouts, characters and costumes. It should be rather interesting.