Latino Review - who've picked up the "rogue nerd-gossip" slack in a major way now that AICN etc have gone a little more legit - have been the go-to guys for scoops on Warner Bros. haphazard scramble to get "Justice League" onscreen, most recently outing Darkseid as the film's apparent (and really kind-of anticlimactic) heavy. Now they've got a new piece of (possible) news: Will Beale's screenplay for the film might be based on a three-issue JLA story-arc from 1980, "Crisis on New Genesis," which involved the League and the Earth-2 Justice Society meeting up with Jack Kirby's "New Gods" characters, of which Darkseid was the main antagonist.
Prior to "Crisis on Infinite Earths" uniting the DC Multiverse, the Justice League books would do annual crossovers with JSA which would typically involve the discovery of more new worlds and characters, which would always be called "Crisis on ______." JLA 183 - 185's story was one of those, essentially serving as a "welcome to officially hanging around on our margins!" to the New Gods (while published by DC and technically taking place in the DCU, Kirby's New Gods books were kept mostly at arm's length from the rest of things prior to this.)
Some sites find this a lot more exciting than I can manage to. With all congrats to LR for landing another scoop, that the screenwriter of a comic adaptation might be starting out with a story featuring the goodies and baddies he's been given to work with isn't exactly Watergate. The idea that, since this was a Multiverse story, it might indicate that Warners might be looking to play that card to get out of continuity hiccups (re: the JLA movie's Superman, Batman, etc. all coming from different universes instead of just not having run into eachother before) is interesting... but I can't really see them going there.
A brief glimpse of Christian Bale, Brandon Routh etc flashing by on a monitor while someone monologues about a Multiverse as a wink/nudge throwaway gag? Sure, that I can picture (be pretty cool, too.) Or maybe this would be the way to get Joseph Gordon Levitt's Detective Officer John Robin Mary-Sue Blake Esquire into the movie for a bit ("On my world, Batman died!") thus establishing some obligatory link with the "Nolanverse" while still having a Bruce Wayne Batman in this one. That I could get behind, absolutely - great way to move on from that series without having to "overwrite" it.
But, really... Occam's Razor pretty-much says that they're gonna fight Darkseid because he's the most recognizable League-level threat from the animated series and WB has told everyone to start name-checking "Crisis on New Genesis" because they figure "don't worry, we're reading the material!" will mollify worrisome fans. We'll see.