During an interview with Total Film, Mark Ruffalo has shared a few details about Bruce Banner’s role in Avengers: Age of Ultron, as well of course as that of his alter-ego, The Incredible Hulk…
“Banner’s been living in Stark Tower. They’ve been working side by side and Bruce has his own lab now. He’s doing work that augments Tony’s own, which could lead to an experiment going wrong… His relationship with Natasha [Scarlett Johansson] deepens. There’s something similar about the two of them. I see them as lost souls. They’re kindred in some ways.”
And as for the Green Goliath: “[Banner’s] ability to handle the Hulk really gets thrown into question in this film. The hard part is coming back. Hulk doesn’t want to cede his place. It’s much harder to come back from being Hulk than it is to get into him. I think there’s a whole other chapter we haven’t seen yet where you find the other nuances within [The Hulk]. The battle of identity going on between him and Banner is all about establishing dominance. The only thing that Hulk is really afraid of is Banner. That’s an interesting dynamic.”
Avengers: Age of Ultron is set for release in the UK on April 24th 2015 and North America on May 1st 2015, with Joss Whedon directing a cast that includes Robert Downey Jr. (Iron Man), Chris Evans (Captain America), Chris Hemsworth (Thor), Mark Ruffalo (The Incredible Hulk), Jeremy Renner (Hawkeye), Scarlett Johansson (Black Widow), Don Cheadle (War Machine), Cobie Smulders (Maria Hill), Samuel L. Jackson (Nick Fury), Paul Bettany (JARVIS / The Vision), Aaron Taylor-Johnson (Quicksilver), Elizabeth Olsen (Scarlet Witch), Hayley Atwell (Peggy Carter), Idris Elba (Heimdall), Tom Hiddleston (Loki), James Spader (Ultron), Thomas Kretschmann (Baron Strucker), Josh Brolin (Thanos) and Andy Serkis in an as-yet-unconfirmed role, thought to be that of Uylsses Klaw.
https://www.youtube.com/watch?list=PL18yMRIfoszH_jfuJoo8HCG1-lGjvfH2F&v=3n3TnGczwV4&feature=player_embedded