Here are Kevin Feige's comments from September.
Do I think Hulk can carry a movie and be as entertaining as he was in Marvel's The Avengers? I do believe that. I do believe he absolutely could. We certainly are not even going to attempt that until The Avengers 2. So there's a lot of time to think about it.
Part of what's fun about the way we played him in Marvel's The Avengers is the ensemble quality of it. I think the pathos and humor showcased a different element of Hulk that's there in the comics, and was always inherent in his character. But when he was so brooding in his other two films, he didn't get to have that wry sense of humor."
El Mayimbe from Latino Review confirmed last night that as of this moment, Marvel is planning to send Hulk into space at the end of The Avengers 2. He has become to hard to manage, and will be banished from Earth. This will set up Planet Hulk, which was already turned into a feature length animated film in 2010.
The storyline originally ran in The Incredible Hulk comic books in 2006, and saw Hulk being banished by all of the Marvel heroes. He lands on an alien planet called Sakaar, where he is enslaved and forced to participate in gladiatorial events. He becomes a hero of the rebellion against the Red King and eventually becoming ruler of the planet. He later returns to Earth for his revenge.
The events seen in the Planet Hulk live-action adaptation will set up The Avengers 3, which will utilize the World War Hulk storyline, and see all of Earth's heroes battling Hulk and his space army. Here, Hulk will come seeking his revenge on the people that banished him. The story will have the newly crowned king of Sakaar beating the superhero ensemble into submission and pitting them against each other in a Hulk hosted gladiator games.
Hulk won't be seen in any of the Phase II films leading up to his appearance in The Avengers 2. His expulsion from the planet will be spearheaded by Doctor Strange, who will be introduced here before his own Marvel Phase III stand-alone movie.
Mark Ruffalo is currently signed for a total of six movies with Marvel Studios.
Iron Man 3 will be hitting theaters May 3, kicking off Phase II, followed by Thor: The Dark World on November 8th, Captain America: The Winter Soldier on April 4th of 2014 and Guardians of the Galaxy a short time later. Phase III of the franchise will feature Ant-Man in 2015 and a possible Doctor Strange film that has not been confirmed as of yet.
Avengers: Age of Ultron comes to theaters May 1st, 2015 and stars Aaron Taylor-Johnson, Scarlett Johansson, Robert Downey Jr., Elizabeth Olsen, Chris Hemsworth, Chris Evans, Cobie Smulders, Jeremy Renner. The film is directed by Joss Whedon.