Marvel Studios will eventually get around to producing Iron Man 4.  The immense success of IM3, which earned $1.21 billion last year, would appear to indicate that an IM4 movie would be inevitable, especially considering that the first Iron Man film was the movie that put Marvel Studios on the map and set the table for one of the major success stories in modern Hollywood.
 
But when Marvel Studios, with its "one sequel and one new character movie per year" plan (see "Marvel Studios Planning One Sequel and One New Character Film Per Year"), finally gets around to making Iron Man 4 will Robert Downey, Jr. still be donning the armor?  When asked if he would be playing Tony Stark in a fourth Iron Man film by Entertainment Weekly, Downey was a bit guarded, saying that it was up to Marvel to come to him with a proposal for more films, if and when the studio decides that they want Downey, Jr. to continue to play Iron Man.
 
The only possible fly in the ointment could be Marvel Studios’ Ike Perlmutter’s legendary cheapness.  According to Forbes, RDJ was the highest paid actor in the world last year, largely because of his “back end” participation in the mega-successful Iron Man 3.  If future Marvel Studios films don’t quite replicate the success the studio has enjoyed so far, will there be a temptation to cut back on the cost of production by switching to a less expensive thespian?
 
But it is hard to imagine another actor in the role of Tony Stark, which Downey has made very much his own, and Downey does not appear ready to retire of his own volition, using a boxing analogy in his reply to EW, "It’s that thing of: Why give up the belt when it feels like you can barely get jabbed?"  But then the actor, who is well aware of the behind-the-scenes machinations of Hollywood, "Most people are saying that right when they get knocked out."