An online game store from New Zealand named Mighty Ape further strengthens the suspicion that Sony Santa Monica is currently working on the latest series of God of War. The store is clearly putting the release date of God of War 4 for September 2012, Sony itself does not provide any official information related to this. One is for sure, John Hight, boss of Santa Monica in the past had claimed that life as a God of War franchise will continue to live even though Kratos had closed the series in a trilogy.
As far as what the truth of this rumor, it is still too early to ascertain as a fact. Sony declined to comment, and a lack of evidence that bodes well for not much hope. But I'm sure touched back a series God of War is definitely a dream of many gamers. Kills more deities with blood? Why not!
From : http://www.jagatreview.com/2011/11/god-of-war-4-akan-rilis-tahun-depan/