A member of the beyond 3d forums has once again taken the games screenshots and measured the games native resolution to find that the game only runs at 1120x585.
Updates:
This story was taken from the Neverending Upscaling/Resolutions/AA etc Thread over at Beyond3d Forums. This is the same source that has verified other high profile game's (Halo 3, Haze, GTAIV 360/PS3, COD4 360/PS3, etc.) native resolutions.
