In an SEC filing made this morning, Activision cited a human resources investigation.
The Company is concluding an internal human resources inquiry into breaches of contract and insubordination by two senior employees at Infinity Ward. This matter is expected to involve the departure of key personnel and litigation. At present, the Company does not expect this matter to have a material impact on the Company.
The two senior employees are assumed to be Jason West and Vince Zampella. One of the studio heads, Jason West, has confirmed through his Facebook and LinkedIn page that he is no longer employed. This must be some serious insubordination to get fired over, especially since they helped shape the best selling video game of all time.

Check back as news/updates are confirmed and hopefully officially addressed by Activision.
[Via G4 Feed]


[...] interesting to see what major titles Gears 3 will be up against, especially given the recent near-demise of Infinity Ward and Modern Warfare [...]