As of right now, the only concrete things we know about this "Justice League" movie is that it's being scripted by Will Beall, who after having written for the milquetoast ABC mystery series "Castle" is now Warner Bros.' favorite go-to scribe (he's written "Gangster Squad" and the proposed Nicolas Winding Refn-directed, Ryan Gosling-starring "Logan's Run," is working both on "Justice League" and at one point was trying to craft on an iteration of "Lethal Weapon 5"); that the studio is targeting a possible summer 2015 release date (the same summer as "Avengers 2!" Whoa! Nerdgasm overload – clear the room, people!); and that Ben Affleck most assuredly will not be directing it. (Although, hey, The Wachowskis might. They might as well, considering the flying stuff in "The Matrix Reloaded" and "The Matrix Revolutions" was better than anything in Bryan Singer's tepid "Superman Returns.")
Beyond that, specifics are hard to come by. But it seems likely that Henry Cavill's Superman (to be introduced in next summer's "Man of Steel") will be a part of the team, so should Ryan Reynolds' Green Lantern (because lord knows he's not doing anything, especially a "Green Lantern 2") as well as a whole host of characters who have seemingly been stuck inside an impenetrable prison that not even a superhero can break through – development hell. This includes characters like Wonder Woman, The Flash (there have been more drafts of a standalone script than characters inhabiting the Flash costume); and Martian Manhunter.
DC/Warner Bros. could have stumbled upon the perfect template – a lot of these characters would probably strain to carry their own movie, as "Green Lantern" painfully proved (can you imagine a Martian Manhunter movie? Neither can we), so introducing these characters in small doses and then gauging the audience's interest seems like a good way to go. These are obviously massive gambles, expensive and complicated, so it might be nice to know which quantities audiences will turn out for.
We just wish DC would follow the Marvel model in terms of bringing in people from the comic book world to help them fashion their new superhero line-up. It would be nice if someone like Grant Morrison, a certifiable mad genius and shepherd of much of the comic book DC universe in the past few years (also: an incredibly dapper dresser), could oversee both the Batman being shaped for the "Justice League" feature and how that character could be brought to fruition in his own feature. Just putting it out there, guys. You know how to get a hold of him. He's probably in his Scottish castle, looking cool as fuck.