Though publisher Activision already has three Call of Duty titles in the works--Treyarch's Call of Duty: Black Ops, Sledgehammer's untitled action-adventure entry and, according to court documents, Infinity Ward's Call of Duty: Modern Warfare 3--the company is reportedly "flipping out" about the unfolding situation at series creator Infinity Ward.
That situation kicked off in March 2010, when Activision fired Infinity Ward co-founders Vince Zampella and Jason West citing "breaches of contract and insubordination." Since then, approximately thirty-five others have left the Call of Duty: Modern Warfare 2 maker of their own volition and Activision has been served with two related lawsuits.
As for Raven Software, Kotaku's source added that the studio's two projects--a James Bond title and an unannounced follow-up to X-Men Origins: Wolverine--have been put on hold in the wake of its "path to Call of Duty development."
[Update - 10:15pm CST] According to G4's sources, "Activision has tasked Raven Software with making Call of Duty: Black Ops map packs." Thanks the archvile.