The Nolan Batman could not work in a JLA movie IMO, he is too realistic.  What could a director do with a Batman movie to make him more like in the comics, where his genius and detective skills are his true prowess?  Also, how do you think he would work in a JLA movie?

It could work. Let's see how Nolan handles superman, and then we coud judge better. Otherwise... I'd say the Val Kilmer Batman might work.

Batman would work...but to have him work in a Justice League movie, you have to make him the ultimate badass...otherwise people will wonder what he's doing in a team like the league.

You want Batman in a JLA movie? Give him some fantastic threats in his next trilogy, rather than "realistic" characters like Two-Face or Ra's. (i.e. Clayface, Poison Ivy, Mr. Freeze, etc)

In other words, make Batman fight and beat someone with powers/abilities out of his league.