Downey is close to signing a deal to co-star in Captain America 3. The sequel will use the “Civil War” comics storyline, where the Superhero Registration Act mandates that anyone with superhuman abilities register with the U.S. government and agree to act as law enforcement. Captain America opposes the legislation, but Iron Man supports it, setting up Downey to play the villain.
It will be interesting to see a different facet of the Iron Man character and create new storyline possibilities for the future of these characters. In the meantime, Downey will be back in next summer's The Avengers: Age of Ultron, which is set for release on May 1st, 2015.
It looks as though Iron Man will not be hanging up his suit quite yet. Downey has proven himself so adept at playing this character that I for one, would not mind seeing him play the wise-cracking superhero for a long time.