Times are looking tough for [The Avengers](movie:9040). From the get-go they weren't the most stable of teams. You're dealing with some superhuman egos to go with those superhuman powers and having a God and a barely controllable green monster among your members doesn't add to a sense of stability. And the events of Avengers 2: Age of Ultron are looking like they'll be splintering the group for good.
Marvel has a couple of Avengers continuing to strike out on their own movie paths in Thor and Captain America, and we might have a better idea of where Iron Man might be headed as well after he butts heads with Steve Rogers in [Captain America: Civil War](movie:994409). But what about Bruce Banner and Hulk? It would seem strange if Marvel doesn't try to do something with the big green guy in the time between Ultron and the Infinity War of 2018.
Setting the Civil War Stage
There are a few things that can point us in some very intriguing directions. Since we know we are on a course to a Civil War, there has to be something that will precipitate these events. In the Marvel comic books it was a devastating explosion caused by a particularly combustible, relatively unknown hero named Nitro. But from the rampaging Hulk that we've already seen from Avengers 2, could it be the Hulk that ends up causing the damage and casualties and forcing the government to step in?
Planet Hulk & World War Hulk
Around the same time that Marvel launched the Civil War storyline in the books, it also ended up sending Hulk far, far away in "Planet Hulk". Deeming Hulk too big of a risk, the Illuminati, including Tony Stark, basically shoved him in a rocket and tried sending him to some peaceful planet where he could retire in peace.
Of course, that didn't go as planned and he ended up on a war-happy planet called Sakaar and Hulk got to play out a whole gladiatorial uprising scenario. He then takes some new comrades back to Earth and enacts revenge on the people who betrayed him. This results in him destroying most of New York, and the Avengers, in "World War Hulk" and getting locked away three miles underground in Gamma Base until SHIELD is convinced they can put Hulk to good use again - once Red Hulk emerges.
There has been eager speculation about a possible Planet Hulk movie practically since the comic book came out. I've always doubted it mostly due to the fact that to make this happen we would be dealing with all Hulk all the time and Bruce Banner, or Mark Ruffalo, would be a negligible factor - and I don't see that happening in any Hulk movie any time soon. While it would certainly be cool to see Hulk battle it out gladiator style against some crazy alien monsters - the movie would be 99% CGI/motion capture and you might as well make it a cartoon - which they already have.
What Would Work
What seems far more likely is that they would skip "Planet Hulk" and "World War Hulk" altogether. Have Hulk destroy New York in Avengers 2 and set the stage for the Civil War, lock him up at the end and get him ready to be another Agent of SHIELD, so to speak. This would leave him out of the Captain America: Civil War equation and have Bruce Banner try to reconcile his split personalities and the damage he has caused in a place where he can't harm anyone.
It would put Bruce Banner and Hulk in the perfect place for a relaunch of his own movie in the form of the Red Hulk/General Ross/MODOK storyline that would provide for a good Dr. Banner plot as well as plenty of Hulk Smash and fight-big-monster material. It's the kind of story that justifies Hulk being out and about and deepens the central Marvel universe. Win Win! What do you think?