Very little is known about the Justice League film that Warner Bros. has planned. All that we really know is the planned release year and that the line-up is said to at least include Batman, Superman, Green Lantern, Wonder Woman and The Flash.
Now, the folks at Latino Review are saying they've learned the villain will be none other than Darkseid. They cite no source, so treat this strictly as a rumor for now.
Darkseid first appeared in 1970 as one of the most powerful of the New Gods. He has unparalleled strength and invulnerability along with his very powerful 'Omega Beam.' The character was the primary antagonist in the first story arc of the New 52 Justice League.
No director is currently attached to the film, but a script by Will Beall (Gangster Squad) has been written. It also remains to be seen if the upcoming Man of Steel and 2011's Green Lantern will tie into the film.