A job listing on SCEA's website, looking for an Online Gameplay Programmer to work on the team that did God of War and God of War II is leading to growing speculation that God of War III will have an online element to it. Now, this is far from confirmation on such a situation, and it's possible that team could be working on another game, but we don't think so.
Also, isn't it more fun to speculate that Kratos will be able to get his gore on online than it is to speculate that there's some other game afoot? We thought so. Besides, GoW fans have to be hungry at this point for any news that's related to the newest game in the series.
Kotaku.com: God Of War III To Feature Online Play?