Now that Zack Snyder is confirmed to direct Justice League after his Man of Steel sequel (popularly known as Batman vs. Superman), it remains to be seen who else is recruited to complete the eponymous DC superhero squad. We have Henry Cavill as Superman, Ben Affleck as Batman, Gal Gadot as Wonder Woman, and Ray Fisher as Cyborg; assuming Snyder's movie follows DC's New 52 comics (which it almost certainly will), that means there's still Green Lantern, The Flash, and Aquman to be potentially cast.
Last night's report that Justice League is a go mentioned that the live-action film is unlikely to reach theaters before 2018, but already that claim is being contested by other news outlets.
The popular rumor right now is that Snyder is gearing up to shoot Batman vs. Superman and Justice League back to back, in order to release them in theaters by 2016 and 2017, respectively; once Snyder finishes his Superman trilogy, it's possible Warner Bros. and DC will then move forward with solo vehicle for such Justice Leaguers as Wonder Woman and Aquaman.
DC's Chief Creative Officer Geoff Johns has teased the possibility of an Aquaman movie in recent times, referring to the Atlantean as "a priority character for the company"; coupled with the fact that the superhero is already becoming a more pivotal figure in DC's animated universe, this lends some credibility to the idea of a bigger-name actor being eyed for the role.
The Wrap reports that rumors continue to persist that Affleck's BFF Matt Damon is "being sought" to portray Aquaman in the DC live-action film universe, though also cautions that the unrelenting claims that Jason Momoa will be in Batman vs. Superman (and maybe Justice League as well) make him just as much - if not more - of a viable Aquaman candidate that Damon.
Damon generally keeps his distance from movie franchises, with such exceptions as the Jason Bourne movies (which he's also stopped working on); it's possible he would make an exception with Justice League, given that his pal Affleck seems to be influencing the project on multiple levels - judging by the hiring of Argo writer Chris Terrio to revise the Batman vs. Superman script. Then again, a younger star like Momoa is arguably the more logical choice to build an Aquaman franchise around; that the Game of Thrones alum would also help the DC-verse cast a wider demographic net, should also be taken into consideration. (In short: the Matt Damon as Aquaman rumor might well be bull.)
With regard to the release date rumors, both Latino Review and THR's Borys Kit are claiming that Justice League will arrive in 2017, in keeping with the long-standing rumor that JL and Batman vs. Superman will be filmed back-to-back. Kit also claims to have "confirmed" that the movies are shooting one right after the other; as far as WB issuing an official release date announcement goes, that might come during the studio's panel at the 2014 International Comic-Con this summer.
That WB/DC won't follow the same formula to universe-building as Marvel Studios has utilized was to be expected, based on recent comments made by filmmaker David S. Goyer - reported to be the "architect" of the DC movie-verse - where he praised Marvel for its success thus far, but also said "I’m not sure that everybody should try to emulate them." Be sure and let us know how you feel about the WB/DC approach thus far, as well as you dream casting choices to fill out the remainder of the Justice League roster.
Batman vs. Superman is currently scheduled to hit theaters on May 6th, 2016, followed by Justice League some time thereafter.