Black Ops sequel greenlit?

That VideoGame Blog reports that Treyarch may have started work on Call of Duty: Black Ops 2 - potentially creating a sub series in the vein of Modern Warfare within the Call of Duty franchise. Given the massive commercial success of Black Ops it would come as no surprise, but it would also mean that we're not seeing a World War II Call of Duty in a very long time. Take it as a rumour for now, but it does make sense with a Blops 2 down the line...