^ Yea, it was a possibility, but they didn't confirm anything. If you watch the ending to GOW III after the credits(SPOILER ALERT!)
You see a trail of blood where Kratos was lying after getting stabbed by the Blade of Olympus, where clearly Kratos survived the death-blow.
I'm not sure if they decided to do a prequel to keep the hype alive for GOW fans, or because they really have absolutely no idea which direction to take the series in, with or without Kratos as the main protagonist.
I think it'd be a bold move not to include Kratos, I mean history has made it clear that fans don't like "change" to their beloved star characters; best examples:
Halloween series: (horror movie not a game I know) but just to reference this, after John carpenter's Halloween I, and II, they were going to make the Halloween "franchise" go in a direction, where every Halloween movie would have a different storyline unrelated to the previous, and contiue the franchise in that manner. Well Halloween III bombed after not including Michael Myers, and people demanded it go back to the original format, which it did and revived the series al2gether.
Metal Gear Solid 2: You were onyl Solid Snake for the "Intro" and the rest of the time you were Raiden.........I myself can say this was an utter piss off as you cannot replace Solid Snake.........e-v-e-r.
Resistance (Fall of Man) 3: They killed off Nathan Hale in the 2nd one, and you assumed the role of the guy who "offed" him at the ending of the 2nd one........not a lot of people were impressed with that, including myself.....Hale was bad-ass, like Nathan Hale to the resistance series was what Marcus Phenix is to Gears of War....
I guess there's the POSSIBILITY of creating a new character to assume the lead role of God of War, but I guess we'll have to wait and see....