Kaz Hirai is moving on from the playstation brand but isn’t going very far at all, as he stays with Sony. This move is merely him moving from the gaming side of Sony to the TV, movies and music side of things at Sony.
Hirari will be staying on the board of directors of the Entertainment portion of Sony, but won’t be actively involved in what goes on.
Sony has not yet made an announcement of who will be replacing him.
News Source (Destructoid)