Batman: Arkham City is the upcoming sequel to action-adventure stealth video game Batman: Arkham Asylum, based on DC Comics’ Batman, for PlayStation 3, Xbox 360, and Microsoft Windows. It is being developed by Rocksteady Studios and published by Warner Bros. Interactive Entertainment and DC Comics. The game was officially announced during the beginning of the 2010 Spike Video Game Awards and is scheduled to be released worldwide the week of October 18, 2011.
PC version delayed again… the soonest you can buy it on PC is on 18. Nov from UK.
You can see the release date and system requirements bellow.