Playable in both 3D and non-3D on the Xbox 360, PlayStation 3 and PC. Call of Duty: Black Ops for Windows PC is NVIDIA(R) 3D Vision(R)-Ready and supports stereoscopic 3D gaming using 3D Vision active-shutter glasses and NVIDIA GeForce GPUs.
Yes, all of the Call of Duty: Modern Warfare games on PS3 have a singleplayer campaign. Some of the campaign modes have a co-op mode, but I'm not sure which of the games has this. Call of Duty 4: Modern Warfare has singleplayer and multiplayer.