This movie simply can't turn out good... | EDIT I was dead wrong
EDIT: I was very wrong and I'm glad :)
Big budget comic book movies simply have no edge needed to make a proper movie where the main character is a deranged and highly intelligent psychopath who dresses up as a clown. To escape the need to explore his character and actions on a deeper level, to appease the young edgy fans who secretly or openly identify with the Joker and to make the movie the least controversial as possible (possibly even child-friendly), they'll either make the Joker a sympathetic character who is out for revenge and traumatized, or they'll take the route of making him a secondary character to the hero who is after him.
Tbh, there's about 1% of hope in me that someone with an ounce of talent and creativity gets in charge of this project and menages to pull it off somehow, but then again, who am I kidding - we should all know by now that movies as big as this are written by a committee of writers who follow the same old cash making formula.