Ruffalo's comments jibe with what Marvel Studios chief Kevin Feige said back in September of 2012 in an interview with MTV.
"Do I think Hulk can carry a movie and be as entertaining as he was in 'Avengers'? I do believe that. I do believe he absolutely could," Feige said, before adding, "We certainly are not even going to attempt that until 'Avengers 2.' So there's a lot of time to think about it."
In early February, the website Latino Review revealed one long-term plan for Marvel involved the Planet Hulk storyline, where the incredible one is sent into space after one too many scuffles with Team Avengers. Whether or not that eventually comes to pass is unclear, but even if it does, it won't happen until much later in this decade.
For now, however, simply expect to see Ruffalo's Hulk in "Marvel's The Avengers 2." That film is set for release in 2015.