A recent job ad posting at Activision developer, Sledgehammer games, seems to confirm that a new entry into the COD family is coming, and Sledgehammer will be doing the development this time around. Sledgehammer was originally supposed to start work on a new title in the Call of Duty franchise, but it worked out that instead they supported developer Infinity Ward on the last COD title.
One interesting twist in the job ad is that it states that the candidate have significant experience and knowledge around the limitations and performance of the current generation of hardware. This could suggest that the new COD title might, in fact, be for the Xbox 720 and PlayStation 4.
While it is known that Sledgehammer has said publically they would like to work with Infinity Ward again, the developer would also like to step from the shadows and produce its own title, as well. We will just have to see how things shake out. Rumors suggest that Infinity Ward is already working on a new unannounced title from the next generation of hardware.