Trailers have showed us quite a bit and many have tried to piece together the story: batman sees the full destructive power of superman, gets obsessed with taking him down, superman fights batman, genetically enhanced clone of zod appears, trinity unites to stop the clone thus starting the justice league.
It's a pretty standard narrative and if it turns out to be true falls a little within the realm of "disappointing".
But what if the trailer is a switch-up from what is really going to happen?
something like this:
WE first see the battle of Metropolis from Man of Steel from the point of view of Bruce Wayne. This incident spurs Wayne to once again don his identity of the masked vigilante known as the Batman, cracking down on crime in Gotham city with a vengeance. A scene with a tattered Robin suit shows that batman gave up his crime fighting days after the death of Robin. His controversial act of allowing the perpetrator to get away with just incarceration caused all his former allies to distrust and leave him.
Scenes of Wayne reclaiming the mantle of the Bat are interspersed with Superman first answering to a committee hearing about the battle of metropolis and the lives lost.
During that hearing, superman pledges to be a force for good and begins carrying out heroic deeds across the world starting with the rescue of a near fatal space rocket accident.
As time goes by, Superman slowly gains the trust and approval of supporters.
At the same time, Batman steps up his battle on crime to the point where Gotham city has come to fear him and his brutal methods. He initiates what history would come to call "The Long Halloween" in which Batman relentlessly hunts down every single one of his rogues gallery, beating them up to near the point of death then throwing them into prison. This begins his "reign of terror"
A year later, Superman is hailed as a hero of Metropolis and a statue is erected in his honour.
By this time, Clark Kent (possibly fuelled by his success as Superman) starts getting a big head and ambitious (taking on the batman as a reporter), desperate to bring justice to a city that is plagued by a vigilante (Gotham). He has his suspicions on a connection between Wayne and the Batman (suspects Wayne is supplying funds and technology to the vigilante).
At a elite social event, Clark meets Bruce Wayne and he has ideological disputes with Bruce Wayne, setting up the conflict. We are introduced to Lex Luthor, a business competitor to Bruce Wayne. Desperate to topple Wayne as a business competitor, Lex befriends Clark in hopes to ride on some positive journalism. Remember, even with his powers, clark is still a rather naive farm boy at heart and gets suckered by luthors's sweet talk against Bruce Wayne and the batman and feeding Clark's desire to dig out the truth.
The clone of zod appears at this point. Lex's plan was to destroy superman and with Lex at this event, he would have the perfect alibi for innocence. Bruce goes into action as Batman, single handedly taking on the clone with an array of impressive weapons. But he is no match and lures the clone into the open while fighting a retreating battle.
Superman arrives and manages to hold off the clone for a while until Batman returns with more firepower.
Batman rains machine gun fire down on the clone who retaliates with a heat vision blast that crashes the Batplane.
As the clone prepares to finish them off, Wonder Woman appears.
After a prolonged battle and the help of Wonder Woman, superman is forced to use devastating means to take out the creature.
His brash actions and show of power frightens batman and the world. Wonder Woman leaves and we get a sense that she is planning something after being shocked at the extent of superman's unchecked might.
>Superman turns the corpse of the clone over to to lex Luthor to uncover the origin of the clone, not knowing that it was lex who was the creator.(we see this in flashback either at this point or a later point)