If you choose to play the next Batman game on PC, Eidos released the official specifications. Batman: Arkham Asylum hardware requirements:

Minimum:

• CPU: Intel single core 3 Ghz or AMD equivalent
• Memory: XP = 1 GB, Vista = 2GB
• GPU: Shader Model 3 NVidia 6600 or ATI 1300 or higher

• CPU: Pentium D 3Ghz or AMD Athlon 64 X2 3800+ (Dual core)
• Memory: XP = 2GB, Vista = 3GB
• GPU: NVidia 7900 GT or higher