they have rufallo signed on for something crazy like 8 movies if they still want him. i assume they'll have a hulk movie soon.
The deal was for 6. So I imagine throughout Phase Two he'll be in after credits scenes, maybe focusing on the scientist side of Bruce Banner researching the Tesseract's powers? Or maybe even part of the Infinity Gauntlet leading up to Thanos?
I saw this the other day, I hope they use Phase Three as Civil War, and Hulk being on another Planet is how they set it up in the comics, they could also have him return for World War Hulk in the fourth phase, which would awesome. Although by then everyone probably would have been recast ahaha.