Re: Next Batman Villain?
I think if they want to have a Batman compatible with Justice League, perhaps bringing some fantastical Sci-Fi characters would be appropiate. The best of them: Mr. Freeze.
I still think The Riddler could be a great villian given the chance. Either way, they must give glimpses of a larger rogues gallery. And yes, let's bring the Joker too, but save him for a sequel.