According to actual ink-and-paper source
PSM3, work on
God of War 4 is already under way and should be ready to decapitate retail shelves in September of next year.
“PSM3 has heard from another source that God of War 4 is coming, and will hit in September 2012…Our source works closely with the God of War universe, and let slip he’d be working on a related project at the same time.”
Despite being able to name an exact month for release, any release date for a game that is still well over a year away from getting into players’ hands should be taken with a Titan-sized grain of salt.