When it comes to Jonah's casting, I really hope he chooses Riddler. Especially with his performance in Moneyball; it could offer a chance to have a very analytical and observing Riddler, on-top of whoever they get for Oswald.
Personally, I could see if it is a reboot; to cherry pick what exactly is and isn't canon going forward (such as Commissioner Gordon [which, a fascinating choice], Batman's past actions with the League, and how Alfred will be handled (whether they continue with Jeremy or go with someone completely new)).
Admittedly, I get the feeling that Birds of Prey and The Suicide Squad might help us boil down just a bit of what to expect.