Robert Downey Jr. has signed on to reprise his role as Iron Man in the second and third installments of the series, as well as the forthcoming Avengers franchise launch, reports Marvel Entertainment.  The first Iron Man film has grossed $578 million in worldwide box office, and Downey Jr.‘s portrayal of Iron Man (Tony Stark) is regarded as crucial to the success of the production plan.

Not so Terrence Howard (who played Stark’s friend Colonel Jim Rhodes in the first film.)  Howard has been replaced in the role by Don Cheadle, who’s signed a contract that will have him appearing along alongside Downey Jr. in Iron Man 2 and 3 and the first installment of The Avengers.  Rhodes will eventually become an armored crime-fighter in his own right, as Iron Man’s ally War Machine.

Also returning, at least for Iron Man 2, is director Jon Favreau.  Favreau will executive produce the first Avengers.

Iron Man is the first film entirely self-financed by Marvel Studios (the film division of Marvel Entertainment) which gives the production company more freedom to allow the iconic characters of their comic books to appear together.  The Avengers was Marvel’s original crossover title, uniting the greatest heroes of its early “Silver Age” (other than Spider-Man and the Fantastic Four.)  This film version will feature Iron Man, the Incredible Hulk, Captain America, Thor and others working together against a major (as yet unrevealed) villain, and the ultimate aim is to launch successful franchises for several of these new characters as well.