According to Latino Review the DC movie Dwayne The Rock Johnson was rumored for is Justice League, and the plans are to shoot it back to back with Batman vs Superman:
“A trusted source says that the unnamed DC film that Dwayne Johnson will be working on in 2014 will, indeed, be a Justice League movie. That’s not all, though, because this has folks wondering how the JL movie can be underway in 2014, when WB/DC are in full-swing production of BvS. Well, the current thought amongst some insiders is that Batman vs Superman and Justice League are going to be shot back-to-back, ala The Hobbit films, the Pirates of The Caribbean sequels, and the latter two Matrix flicks.”
They go on to say the reason is to maximize everyone’s schedules.
Perhaps that’s why we’ve been hearing about so many additional characters?
Batman vs. Superman (or whatever) was scripted by David S. Goyer from a story he co-created with Zack Snyder, with rewrites by Chris Terrio. Snyder is directing. Man of Steel‘s Henry Cavill will reprise his role as Superman in the film, Ben Affleck is Bruce Wayne/Batman and Gal Gadot is Wonder Woman. Amy Adams, Laurence Fishburne and Diane Lane will also reprise their roles in the sequel.
It is scheduled to hit theaters on July 17, 2015.
Source: Latino Review