Though the next Call of Duty installment has not yet been announced by Activision, rumors surrounding the game continue to grow more and more substantial. Today, the LA Times released a report which stated that Infinity Ward was working alongside Sledgehammer Games for the single-player portion of Call of Duty: Modern Warfare 3. According to this report, the support from Sledgehammer Games was needed after the founders of Infinity Ward and several key-members of the development team left Infinity Ward last year.
Additionally, the LA Times claimed that Raven Software, which has also been working on the creation of downloadable content for Call of Duty: Black Ops, was involved in the development of the multiplayer aspect of Modern Warfare 3.
Before joining Infinity Ward in the development of the third Modern Warfare game, Sledgehammer Games had been working on a spin-off from the Call of Duty series, which was supposedly scheduled for a release somewhere in 2011. It is unclear how this cooperation with Infinity Ward will affect the production of this other, currently undetailed title.