Pro-G's writes:
"Co-op play for Call of Duty 4
The Rumour: While Call of Duty 4 is a truly amazing single and multiplayer FPS, it's lacking one thing: co-op play. Well, we've heard that it might not be missing forever.
Verdict: Adding cooperative play to a game post-release isn't unheard of. Rare added co-op to Kameo and with downloadable content being all the rage these days, we wouldn't put it past Infinity Ward to deliver the goods. Don't bank on it though.
Plausibility rating: 2/5"