To help get it done and out the door, Sony has drafted in outside help from some of its other first-party studios. Interestingly, those studios aren't from Japan, they're from Europe and the United States.
Asked by Wired to confirm a rumour that Sony Santa Monica (God of War) was pitching in on the project, Sony Worldwide Studios boss Shuhei Yoshida replied "Well, you know, it's not just Santa Monica. We have great tech people in Worldwide Studios. We have a central tech group in the U.S. and the U.K. so we are giving them whatever help they need. Technically, we have the best engineers in the U.S. and Europe, so these teams are helping them, giving advice."
I don't care if they call in studios from Mars, so long as this game gets finished.