Officially speaking, things have been quiet on the "Justice League" front; while the film is in development, movement has been a little protracted. However, the rumor mill is practically ablaze at the moment; not only has Zack Snyder seemingly softened on "Man of Steel" being unconnected to the team-up, but rumors insist that Warner Brothers is courting Joseph Gordon-Levitt to take on the Batman role.
Of course, Gordon-Levitt already did that at the end of "The Dark Knight Rises," and Christopher Nolan has insisted that the film would close the door on his films and his universe. However, according to Drew McWeeny, the studio may have different ideas about that, as it's reportedly in advanced negotiations with the actor.
In fact, McWeeny's sources are insistent that the Gordon-Levitt will "absolutely be appearing in Justice League" as the new Batman. Not only that, but he may be appearing as Batman even sooner since the crossover is still a couple of years away.
As such, these same sources indicate that both Gordon-Levitt and an unspecified actor from the Nolan films are being recruited for an unspecified project. Could the end of "The Dark Knight Rises" actually be a launching point after all? While it seemed more like a cherry on top after Nolan's adamant claims that there would be no follow-up, it's certainly looking serendipitous for Warner Brothers at this point.
If you combine these rumors with Snyder's coyness surrounding a possible connection between "Man of Steel" and "Justice League," it's easy to let the speculation run wild. One can easily imagine Warner Brothers taking the Marvel route by adding a post-credits tag that will finally bring Batman and Superman together on screen and launch right into Justice League.
This approach might lead to some issues since shoe-horning the Nolan universe into a larger DC universe runs contrary to the director's vision, but it's also a shortcut that would be difficult for the studio to ignore. It needs to jump start "Justice League" quickly, and this is its opportunity to do so. Don't be surprised if it takes it.