As I recall, the storyline for the script was that Batman had been around for a while, gotten married, semi-retired, etc... but then along comes Superman who has a super-fight, and in the battle, somehow Bruce's wife is killed as a bystander. In this version, in order to keep up with Superman, Batman makes a deal with Satan or something and gets magical powers in order to stay toe-to-toe with Superman until, of course, they had someone else to go fight.
|Never make a deal with this guy|
If you're keeping score, even WB - the people who brought us Catwoman, Jonah Hex and Green Lantern - decided against the green light on this script, maybe deciding we first needed to remind America what Superman looked like.
Well, when Man of Steel did pretty well, but word of mouth wasn't all that great and it wasn't clear WB could just roll out a Superman sequel and expect success, they finally went ahead and pulled the trigger on the Batman/ Superman meet-up, and - if nothing else - they hopefully finally got it out of their system and came up with a product that will give everyone the same entirely unsatisfactory match-up that's occurred in every superhero comic, ever, where neither wins and they become friends so they can go off and fight the other threat that was a bigger deal than their little misunderstanding.
Here's the new trailer, by the way.