Follow up tweet from Devin...
Devin Faraci@devincf
Batman's origin is the key to WHY Batman & Superman team up after their initial fight.
So, what we've learned is that Batman's origin is the opening of the movie - likely part of an opening credit sequence of sorts - then we jump to Affleck's Bruce Wayne arriving in Metropolis in some way
during the climactic Superman/Zod Fight from last movie. From there, we cut to two years later, and catch up with the characters in present day...
Lous and Clark are living together, with Clarke objecting somewhat to the stories he's forced to cover at The Daily Planet. He instead wants to be covering/researching this mysterious Batman character he's heard of (who I assume is back in Gotham by now, but who knows). Either way, I actually really like the set-up here: Batman doesn't trust this alien who's come to Earth, so he goes to Metropolis to investigate. Clark then likely hears whispers of this vigilante Batman character, and ends up covertly investigating him as well. One uses his detective skills, the other his journalist skills, and they investigate each other. There's a lot of distrust and covertness going on here, which I kind of love.
Throw in Luthor, who's helping to rebuild Metropolis after the events of the last movie, and is potentially painted as somewhat of a savior/philanthropist of sorts, at least initially. Batman's "cover" for investigating Superman is Bruce Wayne, who presumably teams up with Luthor in some way to also help with the clean-up. Luther and Wayne even share a mutual distrust of Superman, which is also cool, but you can tell that their business philosophies/practices will be totally different, and could be a nice source of conflict as well. Eventually, Wayne will no doubt uncover some sinister Luthor plan (involving Doomsday), and then finally team up with Superman to take him down (a team-up which also in part has something to do with Batman's origin, apparently).
Honestly, this all sounds pretty organic to me, and I like the drama/conflict potential. As long they keep the Wonder Woman / Aquaman / Flash cameos to a minimum, which is what they're doing apparently, I'm fully on board with the broad strokes of this basic plot. Hopefully not only has Superman learned from the mistakes of the last movie, but the filmmakers as well...