PSUni: In an excellent and in-depth interview given by Mark DeSanto at I. Eat. Games, Sony Santa Monica's senior producer Steve Caterson has revealed that the team deliberately slows God of War III's framerate down from 60 frames-per-second for cinematic effect. Though this concept sounds a little odd at first, the team has built the game's technology around making such changes in framerate as smooth as possible. Make sure you read the context of this quotaiton before jumping on Caterson's back.
Update [UPDATE] - Sony Santa Monica’s director of technology, Tim Moss, has corrected the above quotation (and our interpretation) by explaining that although the team does slow down the action in God of War III, this is not the same as the framerate dropping: