We take these kinds of stories with a grain of salt, but we feel they're worth reporting in case something materializes.
A South African retailer called BT Games has started taking preorders for God of War IV, with a tentative release date of February 2013.
We're willing to bet that the retailer is betting on God of War IV being in development. Given the success of the previous titles, it's doubtful that the franchise has been put to rest. It would be no surprise if Sony has another game in development.
We'll be getting in touch with Sony to see if they can confirm the story.
Source: GE