I didn't see a thread on this (somewhat old news though) so I thought I'd post a link to the trailer for this upcoming game.
Batman: Arkham Asylum:
After a massive manhunt the Batman has captured and returned the Joker to Arkham Asylum for imprisonment. But not all is as it seems. As soon as the Joker is back inside the asylum, it is revealed that he has set a trap for the Batman, using the Asylum's own impenetrable defenses against him. Batman must now not only try to escape from the hazards of the Asylum, but also recapture the Joker and reveal his true intentions.
Also seems to be a reunion of the Batman TAS Cast (but the Joker sounds more like the The Batman Joker to me than Mark Hamill).