While fans are eagerly waiting for 'Avengers: Age of Ultron' rumors have started building up about third installment to the franchise. With Robert Downey Jr. uncertain about returning as Iron Man after 'Avengers 2', speculations are high about fate of rest of the cast and how things will change and affect the franchise.

The way Robert Downey Jr. is playing with his fans is now getting to the point of pranking. After joking that 'Iron Man 4' is only possible with Mel Gibson directing it, Downey confessed the true progress of the film on Ellen DeGeneres' show. But there is no official announcement yet from the studio about the character's future.

While 'Thor 3' and 'Avengers 3' are confirmed for the post phase 2 era of Marvel movies, the cast might change radically in the third sequel. The events in 'Age of Ultron' will trigger the change and the third installment in the franchise will work as"the springboard to ... something else," an insider source told IGN.

It is also a possibility that Robert Downey Jr.'s Iron Man will become the new leader of Avengers in this upcoming movie. The movie may work as the first part of the epic finale for all the characters and will see them reunite in second part, i.e. 'Avengers 4'.

Ant Man, Doctor Strange, and Black Panther are expected to be the new Avengers, while hopes are high on Wasp and Mockingbird as well. However, casting for these characters has not been done. Also expectations are strong about Avengers and Guardians of Galaxy's teams joining for the third movie.

Meanwhile, Daniel Radcliffe was spotted in talks with Marvel about doing a movie with them. Fans are hoping that he lands the role of Stephen Strange in the upcoming 'Doctor Strange' film.