3D is going to be available in Call of Duty: Black Ops which gets released November 9th.
The Xbox 360, PlayStation 3, and PC version are only supported for 3D. You are obviously required to have the technology to play in 3D. You do not have to buy a separate version of the game either (disc). The ability to play in 3D is included as an option to turn on/off in each version of the game (Xbox 360, PS3 or PC).
For all you Xbox 360 users out there, to also further play in 3D, you must be using an HDMI cord, and not component. It is also only compatible in 720p mode, not 1080i or 1080p.
As taken from the Call of Duty: Black Ops 3D FAQ:
DO I NEED A SPECIAL TELEVISION OR COMPUTER MONITOR TO PLAY THE GAME IN 3D?
Yes. Call of Duty: Black Ops can output 3D signals for televisions that implement an active-shutter stereoscopic 3D technology. Xbox 360 users need a television that supports a “side by side” 3D mode. PlayStation 3 users need a television that supports a “top-bottom” or “over-under” 3D mode. PC users need a monitor that supports Nvidia 3D Vision 3D technology.
NOTE: Call of Duty: Black Ops is not compatible with other 3D technologies and/or modes such as anaglyph, polarized, ChromaDepth, or ColorCode 3D technologies. Active shutter televisions that support only a “checkerboard” 3D mode are also not compatible.
Source: CallofDuty.com