Early this week, rumors started spreading like a wild-fire, that Jason Momoa would be playing the King of Atlantis, Aquaman, in 2016's Batman v. Superman: Dawn of Justice. If that didn't already exceed the limit of heroes allowed in one film, Wonder Woman, Superman, Batman, Cyborg, a rep at The Daily Superhero's Insider leaked some more rumors about a certain Scarlett Speedster that would be joining the film's roster.
According to the site, a Flash cameo scene HAS ALREADY been shot for Batman v. Superman: Dawn of Justice. In a robbery scene, a sudden 'flash of wind" can be seen on the security cameras and is confirmed to be a cameo for the Flash.
No official word or announcement has been made by DC or Warner Bros regarding the casting, as this scene doesn't require an actor currently and will be entirely CGI. An actor will be confirmed soon, as Kevin Smith also confirmed that DC's road map is true, so a Flash/Green Lantern movie should be heading into production shortly after the giant assemble of the Justice League.