During a 1UP podcast, it was mentioned that Killzone 2 will come out in 2008 regardless of the quality. However, a community forum leader for Killzone 2 has come out to say they have consistently refused to advance a release date so any discussion of a date is in the realms of pure speculation.
To quote: This silence leaves much doubt and speculation in the minds of many. Shane Bettenhausen of 1UP took it upon himself to unleash one hell of a rumor on the latest episode of the 1UP Yours Podcast. He mentions that he heard, "Killzone 2 will come out in 2008 no matter what the quality". Which implies that the game will be forced into our hands whether it's ready or not.
Killzone.com community forum leader, Guerrilla-E0N had something to say about that.
"Speculation on a rumor based on gossip? We have consistently refused to advance a release date, so any discussion of a date is in the realms of pure speculation, don't you think?"