Thanks to the LinkedIn profile of former Playstation World Wide Studios head Michael Mumbauer, we have learned that the San Diego office are working on a game based on an existing franchise.
Part of about section states:
His latest achievement is having built a brand new, all-star, AAA Action/Adventure development team for Playstation. Based in San Diego and utilizing proprietary engine technology, this team was assembled to expand upon existing franchises and craft all new stories for the next generation of gamers.
Some have speculated this could be a new entry in the Uncharted franchise.