Rumors are the villain might be Darkseid, and that the storyline could be based on the Justice League America issues released in 1980, #183-#185 were written by Gerry Conway and drawn by George Perez which involves Darkseid planning the destruction of Earth by blasting it with a ray thatll move Apokolips (Darkseids planet) into the Earths place. Today, a new rumor has emerged about who will be in the League aside from the obvious choices (Superman, Batman, Wonder Woman, Flash, Green Lantern). The list also includes brief character descriptions and cameos.
Superman is essentially the same character from Man of Steel, and Zack Snyder is consulting regarding the writing of the character.
Batman: The strategist of the group. Batman doesnt really want to be involved with these super powered beings he considers too powerful. Easily the most complex written.
Wonder Woman: She has only been in mans world a few short months. The Wonder Woman script Michael Goldenberg is developing will be set before the Justice League movie.
Green Lantern: Will be Ryan Reynolds character from the Green Lantern movie, but will be freshly written with a more serious tone.
Flash: The most popular hero in civilian eyes who loves media attention, but when called upon is very serious.
Martian Manhunter: Alien who has lived on Earth in secret for over a hundred years who has knowledge of Darkseid and his reign.
Aquaman: Will be the King of Atlantis who has a key role in the film.
There will also be a heavy military presence in the film which in future rewrites could include characters featured in Man of Steel or even Amanda Waller (Angela Bassett) of which neither are included in the first draft.
Alfred Pennyworth is in the film in a minor appearance.
Lois Lane is also in the film in a cameo.
Darkseids Elite will be featured who go up against the Justice League early on in the film.