As for Activision's countersuit and recent naming of EA to it, their main claim is that West and Zampella's behavior was conduct in breach of fiduciary duty and breach of loyalty of duty. To make it short, they allege West and Zampella first conspired with EA through liasions such as CAA no later than July 30, 2009 thus breaking any MOU for future Call of Duty and Modern Warfare brand games, and breaching their contract. The timing of this allegation is prior to the release of Modern Warfare 2, thus rendering the original lawsuit invalid and baseless according to my reading of Activision's countersuit.
I read through it all, but found pages 5, 6, 7, 10, 13-14, 15, and 19-24 very interesting if they have the documentation to back it up.
Source: West and Zampella v. Activision Publishing. http://kotaku.com/5715884/activision-vs-ea-complaint//gallery/2
