Call of Duty on the PC has had a history for not running nativley on multi-monitor setups; we can select the resolution, but the singelscreen FOV vgets stretched across all displays. I was hopinhg this would change once Treyarhc got the reins, but no.
Most games these days have native support, and I eally hpoe this will be the case for Black Ops 2, allowing Treyarch to finally keep up with other games like BF3.
For the past games, a gentleman named Dopefish has been kind enough to create a 3rd party fix for the COD games, and it works quite well. You can find it at www.widescreenfioxer.org. One can find lots of information on the subject at WSGF.org..
Please PLEASE catch up with the technology and give us native multi-monitor support, for once.