Read any article on any of the comic book/movie websites and you will find many rumors about DC Comics/Warner Brothers wanting to produce a Justice League movie. There was even one rumor that suggested that they wanted to come out with a Justice League movie BEFORE coming out with solo movies for the individual characters, doing what Marvel did with the Avengers BACKWARDS.
Personally, I think that's a terrible idea. They need to come out with successful solo movies first. Now, since Nolan's Batman trilogy has been given a distinct ending (with rumors of a reboot) and Green Lantern flopped at the box office, all DC has is Superman IF 'Man of Steel' is successful (hopes are high with many good reviews based on preview screenings). There is no Flash or Wonder Woman movie. Do they give Martian Manhunter his own movie or stick him in cameos during the other films? Who do they include in the JL movie roster anyway (Aquaman? Hawkman? Cyborg?)
At any rate, I think they should reboot Batman BEFORE the JL movie and this is how I would do a new Batman trilogy if I were given the job.
1) OLDER WITH BAGGAGE. Internet rumors from the studios and fans alike agree that the origin story should not be redone, as it was done twice and perfectly in Batman Begins. My Batman movie would star a slightly older, more mature Bruce Wayne who is a respected businessman and not falling asleep during board meetings like Nolan's Batman. Basically, I would take bits and pieces from Nolan's trilogy and create a vague continuity. Most of Gotham's citizens think that Batman killed Harvey Dent, as Commissioner Gordon and Batman concocted a hoax (a year ago) so that the city would not lose faith in Harvey Dent. But he is not dead. Y'know, because he didn't fall that far to the ground in 'The Dark Knight' anyway. He being "rehabilitated" in Arkham and Commissioner Gordon worries about what reactions the citizens (and his superiors) will have when they find out the truth. They made the same deal that they did at the end of 'Dark Knight', but Harvey is not dead and is being held in Arkham as part of the cover-up (and for a big reveal at the end of the first movie...perhaps a post-credits scene).
2) SCI-FI ELEMENTS. I would keep my Batman trilogy almost as realistic as Nolan's...with a slight half-turn towards science fiction elements, so that we can see a better version of a character that was done horribly in the worst Batman movie ever (Batman and Robin)...Mister Freeze. Between the 1992 animated series and newer comic book stories I have read, this character can be done well, dramatically. A man who feels no emotion, trapped in a cryogenic suit trying to cure his wife, showing that he does have emotion. There should be a scene at the end where Mister Freeze, normally stoic, firing his freeze gun, gets emotional and flips out on Batman like Spock did at the end of the Star Trek reboot. His storyline has to do with emotion, so he should just be an evil Spock in a freezer suit. Since Bruce Wayne is older and a respected businessman, it makes sense that he would have a division of Wayne Enterprises called Wayne Tech and be hiring/dealing with scientists like he does in the comics and this would be a perfect way to introduce Mr. Freeze and other characters that are sci-fi slanted, but without making them campy like they have been done in the past.
3) THE VENTRILOQUIST AND SCARFACE. Maybe the studio is afraid of rebooting Batman and doesn't want to throw alot of money at this movie, or at least not too much. Not to worry, I would include one of my favorite villians from the 1992 animated series...the Ventriloquist, a man with dual personalities whose 'other side' is a criminal genius named Scarface, which he manifests through a wooden puppet. He is the head of the mob and the puppet is running the show, even calling the human behind him 'dummy'. This character could be done in a serious way, where he is clearly nuts and disturbing. He doesn't have to be played silly at all and he doesn't require any big budget effects like Mr. Freeze's freezing gun.
4) JOKER. The second movie in this trilogy should play off of the fact that the Joker never died at the end of Dark Knight. He is still in Arkham and is being treated by Dr. Harleen Quinzell (Harley Quinn), a criminal psychologist who falls in love with Joker, helps him to escape and goes on a country-wide crime spree, Bonnie and Clyde-style. I would like to see a story where Joker wants to be a filmmaker and is filming a documentary as he does this. Maybe he terrorizes the head of a movie studio and kills him when he won't fund his movie. Maybe Matt Hagen, the Clayface character (a scarred, washed-up actor who gets the ability to shape-shift) can be involved.
5) ROBIN. Now that Batman is older and trying to be more like his father, taking the family business more seriously and whatnot, maybe he wants to adopt an orphan. I imagined a scenario where Killer Croc (muscle bound half-man, half-crocodile) works at Haley's Circus and Batman first meets (pre-teen acrobat/archery enthusiast) Dick Grayson after he apprehends Croc during a knock-out, drag-out fight. Then, Dick's parents are killed by a man trying to extort money from the circus (Ventriloquist and Scarface? Croc?) and Dick Grayson goes to the orphanage, sneaking out of the orphanage at night, trying to find information on the guy who killed his parents. We only find out later that he was in cahoots with Batman. It is sort of unrealistic for child services to let an orphaned 10-year-old stay with a man who has the reputation for womanizing that Bruce Wayne does...so Bruce tries to adopt, they tell him 'no', but Batman and his young sidekick are still in cahoots (giving him tracking equipment etc.). Oh, and his name 'Robin' does not come from the red bird. Being an archery enthusiast, Dick first wants to call himself 'Hood', after Robin Hood. When Batman sees his first attempt at a costume and points out how dangerous it would be to fight crime with a cape AND a hood. He says "lose the hood. You're Robin." For most of the film, Dick Grayson is helping Batman acquire information and not putting him in harm's way, but that builds up to a great action scene at the end where Robin is firing arrows and ziplining across the Gotham skyline and taking out bad guys. Also, if two of these films take place 10 years apart, that would be great to explore the older versions of Robin (his Nightwing persona and his strained mentor relationship with Batman).
6) URBAN LEGEND. Remember those scenes at the beginning of Tim Burton's Batman movie where the criminals thought Batman really was a giant bat? Or those scenes in Batman Begins where he took out a bunch of Falcone's thugs without revealing himself until later, clinging to the shadows? Well, THIS Batman has maintained that. Some think he killed Harvey Dent. Some don't. But criminals are still afraid of him when he violently yanks their colleagues into the shadows of an alley with a batarang, a sturdy wire and a pulley on his glove. He still hangs upside down, throws gas pellets and then vanishes...ninja style!
7) TWO FACE. As I mentioned, Harvey Two-Face is still alive, but there is alot of drama as far as whether the citizens of Gotham should know that. "Well, the doctor's think he's rehabilitated. We can't keep him locked up if he is sane." "But then people will lose faith if they know the police commissioner lied to them." The Joker plays on this fear, clever as he always is, coupled with the fact that his new squeeze Harley Quinn was Harvey's doctor too, Joker is integral to Two-Face escaping from Arkham and being the villian of the third film.