UPDATE: Infinity Ward has issued a tweet stating: "Interesting news today, but it’s not true. We’ve not talked with any voice actors, so all news is speculation." Which doesn't actually mean anything, but we have to take it into acccount.
ORIGINAL: UK actor Bill Murray (voice of Captain Price in the Modern Warfare franchise) accidentally leaked Call of Duty: Modern Warfare 4 to someone who happened to be a journalist.
Since it's not officially confirmed, you can consider it a rumor to be safe but it's definitely got some heavy credibility, as Murray told what he thought was a random fan, “Yeah, on Monday I am off to meet Infinity Ward about the next game, Modern Warfare 4, I’m doing work on the sequel to Modern Warfare 3, it carries straight on and I only ever appear in the Modern Warfare games…”
It happened on a flight from Bodrum to London when the founder of a gaming news site recognized Murray's voice next to him. It seems incredibly unfortunate for Murray as this same fan ended up leaking his name and likely secret information to the entire Internet.
Sure, Murray was probably just being nice (I mean he even took a picture with the guy) and figuring he was just some guy that might tell a friend or two, but it's still negligence on his part. Hopefully Infinity Ward doesn't get too angry at the voice actor. There seemed to be a lot of ignorance and negligence on all accounts, but the news we got out of it is specifically that Murray will be in talks with Activision and Infinity Ward next week about voice acting in Modern Warfare 4.