Sony Santa Monica promised fans that trilogy ending PlayStation 3 best-seller God of War III would not be the final game in the franchise. And according to a new report, we should expect to see the next installment in September 2012.The latest issue of UK magazine PSM3, citing an unnamed source who "works closely with the God of War universe," reports that God of War IV is now in development. No details on the game are provided other than a release window: September 2012.Speaking with Industry Gamers back in March 2010, Sony Santa Monica Producer Steve Catterson said anything is possible with the future of the God of War franchise: "We didn't leave you on a cliffhanger but I think it's not the end of the franchise," Catterson told Industry Gamers. "I'm looking forward to do something different if we can... Anything's possible."The latest issue of PSM3 is hitting subscriber mailboxes now and will ship to newsstands next week. Any official announcement from Sony about God of War IV would likely come at E3 2011 in June at the earliest.It took roughly three years from God of War II to III, so the early 2010 to late 2012 development timeframe seems right for IV. The question now is, where will Sony Santa Monica take the franchise?