HitFix posted this bit about where things may be going for the Hulk:
WARNING: AGE OF ULTRON SPOILERS ARE BELOW!
Banner continues to play a key role in things in this movie, and when the final war with Ultron spills onto the battlefield and out of the virtual realm, he has a major part to play. Unfortunately, that ends with him onboard a Quin jet on his way off the planet, with no way to immediately turn things around. He’s going to have to ride out the trip. It’s pre-programmed and he can’t stop it.
Here’s where I’d wager his spaceship is headed: wherever the Guardians of the Galaxy are located. If I was a betting man, I’d say there will be no Hulk solo film as part of Phase Three. Instead, Banner’s ship will take him to another planet, where he will end up meeting the Guardians and having an adventure with them. Hulk will definitely come out to play a few times. I suspect we’ll see some sequences that very much feel like they’re part of the Planet Hulk story, but that the larger story will be about the Guardians finding a way to get Banner home, only to end up going with him. That would move a big piece of the puzzle into place to get Thanos looking back at the Earth in time for the third “Avengers” film.
That would be a way to get the Guardians to Earth, and it would be a way to do elements of Planet Hulk as some of those gladiator battles couldn’t be done by Marvel Studios (as they don’t own Silver Surfer). However, this still doesn’t mean the “World War Hulk” Avengers 3 rumor as any truth to it, as Thanos has no part of that storyline and it’s mostly a revenge story for the hulk. This doesn’t sound anything like that, as his departure from Earth seems to be accidental in the movie and not intentional like in the comics.
And by the way, it’s “Quinjet” not “Quin jet”.