Batman: Arkham Asylum will be getting two download packs over the next two weeks, according to the official European Playstation Blog.
Insane Night will hit the Playstation Network (and apparently Xbox Live and PC) on Sept. 17, while Prey In The Darkness will hit on Sept. 24, according to Mike Kebby, with the Playstation Store Team at Sony Computer Entertainment Europe.
Contacted for comment earlier this week, Warner Bros. Interactive would only say that more details would be forthcoming.
Earlier this week Batman: Arkham Asylum’s in-game ticker alerted gamers to incoming new content that would be free.
https://kotaku.com/new-free-content-coming-to-batman-next-week-5354514
Heads-Up – Comments [Playstation Blog EU, via Eidos]
