While Sony's mysterious San Diego studio has never been formally revealed, there has been obvious signs pointing towards their existence for two years. But as time went on, the silence led to rumours about the studio being axed by Sony before they even revealed a single game.
These speculations has now been completely shut down by John Bautista, who recently left the developer. He writes on Twitter:
"Just to clarify, I made the decision to move on due to my own personal circumstances. AFAIK the studio is still there and the project is still ongoing."
So there we have it. It is still very much up and running and hopefully we'll gets signs of life sooner rather than later. As they have a lot of ex-Naughty Dogs hired, it is widely believed that they are the ones continuing the Uncharted series from now on.
Thanks GamingBolt