An article from November 29th by IGN's Colin Moriarty discusses a brief inadvertent update on Playstation's official B:TS page citing a May 5th 2013 release date. The image has since been modified and Sony has stated that an official release date has not been announced. It was previously noted that B:TS recently entered the alpha phase of production which makes a firm release date hard to pin down at this point. Full article and images of the 'leaked' image are here.
An additional article by Gamespot confirming the error is available here.