Infinity Ward doesn't know what its next game is going to be, it's claimed in an interview (read: if it's not Modern Warfare 3 we'll capture and eat a live badger).
Community man Robert Bowling told MTV: "We don't know what our next game is. Once we finish [Modern Warfare 2] we're going to do a lot of DLC support for it and then we'll sit down and talk about, 'ok, what's our next project going to be?'"
He continued: "It doesn't mean that this is the end but right now we're continuing the story and we're concluding some storylines but anything's possible for the future."
When asked outright if the studio is going to craft a third Modern Warfare, Bowling responded: "We always like to leave some opening and some air to breath so you're going to have to play it and see."