I think either way, Activision may have just unleashed hell.
Several things are going to result from all of this.
1.) Their image as a whole manages to (against all odds) actually sink DEEPER into the toilet than it already is.
2.) May have just crippled the Modern Warfare brand name JUST ENOUGH that if EA or another company can get to these two guys, start a new development studio, and produce a game called "Contemporary Strife" or something like that, they might be able to bury any future MW games as pale imitations or as having less fun "quality" (see: Call of Duty World at War)
3.) EA is probably already blowing up their phones... after all, if Activision FIRED these guys, then there is NOTHING at ALL now to keep them from welcoming them with open arms into the EA flock to make a potentially record-breaking game IP for THEM.
4.) I can easily see many IW employees tendering their resumes in order to get join whatever new "studio" these two executives put together independently.
5.) Games come and go, but studio loyalty can be worth it's weight in Gold. There are people who will buy ANY bioware game, because Bioware has had such a decent track record with those people. The next MW game might sport "Infinity Ward" somewhere on the BOX, but it everyone will know it's not the "same". Personally, I wouldn't play a Treyarch "modern warfare" game or a Call of Duty game ever again unless IW was the creator/developer/ and tester.