A trusted industry source has revealed to XBLAFans that Warner Bros is currently working on a Batman game for Xbox Live Arcade. The game, which previously showed up on several UK retail sites under the name 'Gotham City Imposters' is said to now be in development for XBLA. Nothing has been heard of the game since those listings although it had been speculated the name could refer to Batman: Impostors, a comic miniseries.
There is very little information to go on at this time, so we can treat this as nothing more than a rumor. However with the Caped Crusader so popular these days there is merit to the idea that Warner Bros would be looking to extend his reach to the download space. We have contacted Warner Bros for comment but have yet to receive any word.