This is SteamPlay and all Multiplayer will be all BL2 players, PC & Mac. The current DLC will also be available for launch. If you pre-order from GameAgent you some premier club stuff free.
It also supports a lot of graphics cards, unlike Black Ops, so people should be happy.
System Requirements
Minimum System Requirements
Operating System: 10.7.5 (Lion), 10.8.2 (Mountain Lion) CPU Processor: Intel Core 2 Duo (Dual-Core)
CPU Speed: 2.2GHz
Memory: 4 GB RAM
Hard Disk Space: 13 GB
Video Card (ATI): Radeon HD 2600
Video Card (NVidia): Geforce 8800
Video Memory (VRam): 256 MB
Peripherals: Macintosh mouse and keyboard
Supported Video Cards:
NVIDIA GeForce® 8800, GT 120, 320M, 330M, 650M
ATI Radeon HD 3870, HD 4670, HD 4850, HD 5670, HD 5750, HD 5770, HD 5870, HD 6630, HD 6490, HD 6750, HD 6770, HD 6970
Intel HD Graphics 3000, 4000
Gamepad support: Borderlands 2 supports the Xbox 360 wired gamepad only.
Recommended System Requirements
CPU Processor: Intel Quad Core
CPU Speed: 2.4 GHz
Memory: 4 GB RAM
Video Memory (VRam): 512MB
*Apple original CPU's only, CPU upgrades not supported.