God of War: Ascension's game director, Todd Papy, has suggested that Kratos was a bit of a dick at the end of God of War III, but that earlier games, particularly the first one, do display a slightly different side to the vengeful slaphead, and that this is what SCE Santa Monica wanted to bring out by doing a prequel in Ascension.
"With the way that God of War III ended, Kratos, was…um…an a**hole, to say the least.," said Papy, talking to Game Informer. "I think some people connected with him, but it was more of an, 'I've been through this journey with him from the start.' And he wasn't a very likable character, versus God of War 1 – he was still somewhat ruthless, but there was a side to him that you could somewhat relate to. And that was something that I wanted to get across. I felt the best way to do that was going more for a prequel."
We wouldn't worry about Kratos suddenly going all mushy, though. He'll still be ripping the tits of of elephant men and savaging minotaurs with very sharp blades.