A new Batman game is coming to the PC, PS3, and X360 next summer. It's called Batman: Arkham Asylum.
Going for a similar sort of feel as the recent popular Dark Knight movies, the game is going to look towards graphic novels for inspiration. Writer Paul Dini, who worked on Batmam: The Animated Series, is penning the story and Mark Hamill will be reprising his voice acting role as the Joker.
Using the Unreal engine, Arkham Asylum is going to be a third person action-adventure game. Batman will have to use his super-hero detective skills to souse out the criminally insane. Once located, the criminally insane will be beaten up, and hit with various flying Bat-tools.
Rocksteady Studios is behind this project. They are a relatively new studio, with only one other game -- Urban Chaos: Riot Response -- to their name.