Despite retail websites suggesting otherwise,
Batman: Arkham Asylum might not be out until Christmas... according to Game Informer.
Eidos is is sticking the a Summer release date for the moment, however, with a representative telling SPOnG, "The only release date announced thus far is Summer 2009."
The Game Informer report cites "sources close to the game" telling it that the game won't be out until the fourth quarter of 2009. It's not even entirely whether this means the fourth quarter of calendar 2009 (October - December) or fiscal 2009 (January - March 2010 for most US companies). A Christmas release is the most likely bet out of the two, however.
Numerous UK retail websites carry a June 19th release date for the game, suggesting it's release was meant to be less than two months away.
Keep this in the 'rumour' folder for now.
See: Game Informer