Treyarch's posted new job listings which seemingly confirms that work is already underway on a new Call of Duty title at the Black Ops developer.
The studio's website insists it's looking for a gameplay combat designer, who will report to the "Design Director for the Call of Duty multiplayer team at Treyarch."
A job listing for scripter mentions of a "a design test utilizing Call of Duty mod tools."
Other job postings also ask for experience with the FPS genre whilst working on other mentioned jobs such as combat systems and gameplay mechanics.
Treyarch released Call of Dut: Black Ops last November. This year's CoD iteration yet to be announced, though it's expected to be a Modern Warfare 3, joint developed by Infinity Ward and Sledgehammer Games.