Activision has a lot of people working on Call of Duty. Treyarch and Infinity Ward take turns releasing yearly editions of the franchise, getting help from other Activision studios like Sledgehammer and Raven Software. Now it looks like Neversoft, the studio known for building a couple of Activision's biggest non-shooter franchises -Tony Hawk Pro Skater and Guitar Hero - will join the CoD war effort.
The Neversoft website shows that studio is hiring developers with First-Person Shooter experience to "push the genre in support of Activision's Call of Duty franchise. The website doesn't specify whether the studio will take a lead role in the development of future Call of Duty titles, or lend support to current leads Infinity Ward and Treyarch.
According to Joystiq, Neversoft has been hiring for an unnamed shooter since 2010, We can only assume that means the studio has been working on a Call of Duty-related project since then.