The LA Times reports that Sledgehammer Games and Raven Software are helping out what is left of Infinity Ward to get Call of Duty: Modern Warfare 3 ready for November 2011.
According to its sources -- "people close to matter" -- Sledgehammer Games and Infinity Ward are sharing duties on producing the singleplayer campaign. Raven Software is said to be developing the online components for Modern Warfare 3. The sources also claim that this has caused Sledgehammer Games to stop work on the other Call of Duty adventure spin-off it had been working on.
Earlier this month rumors circulated about Infinity Ward not working on a new Call of Duty at all, so take all of this with a grain of salt until Activision announces something. Any way you want to spin it matches job postings like this User Testing coordinator one, which wants you to help Sledgehammer Games create a 95+ rated Call of Duty, and this Infinity Ward Scripter job.
Let's hope for the PS3 fans of the series that whatever new Call of Duty game is released this November, it will actually be considered to be playable online.