By Jeff Jensen
July 24, 2010 at 12:00 PM EDT

Image Credit: Mike Coppola/FilmMagic; Kevin Winter/WireImageRobert Downey Jr. brought a tumultuous day at Comic-Con to a close by announcing that Mark Ruffalo (The Kids Are Alright; pictured left) will play Bruce Banner (a.k.a. The Hulk) and Jeremy Renner (The Hurt Locker; pictured right) will play Hawkeye in director Joss Whedon’s feature film version of the Marvel Comics superhero team The Avengers. The Iron Man star — who was brought to the stage during Marvel’s Comic-Con panel by Samuel L. Jackson, who plays Nick Fury in the Marvel movies — appeared with the other actors who will play the other Avengers, including Chris Evans (Captain America), Chris Hemsworth (Thor), and Scarlett Johansson (Black Widow). The cast announcement was greeted with a standing ovation by the attendees. The movie is slated for a 2012 release.

Ruffalo replaces Edward Norton, who was dropped from the film by Marvel Studios, reportedly due to a contract dispute. In announcing Ruffalo, Downey made like a politican and declared that he “approved of this message.”

Invoking the current box office sensation Inception, Downey — looking like a mod rock star in shaggy hair and tinted glasses — vowed that The Avengers will be even more ambitious than Christopher Nolan’s acclaimed sci-fi puzzle box drama. Marvel’s panel — which also included sneak peeks at the Captain America and Thor movies slated for release next summer — began about an hour late following an assault during a previous panel inside Hall H at the San Diego Convention Center in which one attendee stabbed another in a dispute over seating. Downey joking referenced the attack, saying, “Nobody stab anyone” until he was finished with his announcement.

Pictured left to right are Robert Downey Jr., Clark Gregg (Agent Coulson), Scarlett Johansson, Chris Hemsworth, Chris Evans, Samuel L. Jackson, Jeremy Renner, Mark Ruffalo, Director Joss Whedon, and Producer and Marvel Studios President Kevin Feige.