The Justice League movie has to be much darker in tone than the Avengers....
if they're gonna do a Batman reboot so soon to fit him in that universe, its possible to do another dark toned Batman movie. I'd love to see a Arkham Asylum/City adaption. You can use more of Batman's villains in a world where Superman exists... like Clayface for example.
As someone mentioned, the Nolanverse was about Bruce Wayne. I don't have a problem with seeing a Batman movie where he's a master strategist, not simping over females when his mask is off, master of hand to hand combat and the best detective. The only problem here is that its coming so soon...
That's the problem with the recent Spider-Man.. people outside of the internet actually liked 1 or 2 of those movies and still recognize Tobey as Peter Parker. 4 years from now, everyone will still recognize Bale as Batman and if you wanna use Joker again (which WILL happen eventually), how do you get people to feel comfortable with someone new after Ledger and Nicholson?
Instead of trying to piggyback off the Avengers so soon, I think Superman should get 1-2 movies, Flash 1 movie, Wonder Woman 1 movie and Green Lantern 1 movie within the next 8 years, THEN the Justice League movie which introduces Martian Manhunter.. and Batman will be in it too... THEN a new Batman movie away from the League.