Looks like the GFWL integration is final from the pictures. Isn't going to stop me buying the game a second time for PC though! Do want that mouse and mousepad!
EDIT: Steam preorders now up here: http://store.steampowered.com/app/211420/
Steam doesn't say there's GFWL integration so maybe there's a chance of steamworks?
Comes out August 24th and the system specs are:
OS: Windows XP , Windows Vista, Windows 7, or newer
Processor: 2.6 GHz Dual-Core
Memory: 1 GB (XP), 2GB (Vista/7)
Hard Disk Space: 4 GB
Video Card: 512 MB RAM, ATI Radeon 4850 or higher, NVIDIA GeForce 8800 GT or higher
Sound: Direct Sound Compatible
Additional: Multiplayer requires microphone headset support