The Marvel Cinematic Universe is expanding rapidly, with Guardians of the Galaxy proving such a massive hit, Captain America: The Winter Soldier thought to be one of their best movies ever - and next year's Avengers 2 and Ant-Man highly anticipated.
But what about the movie where it all began, Iron Man? Robert Downey Jr had made encouraging noises at Comic Con 2014, but now seems to be backing away from a fourth Iron Man movie. So what are Marvel's options?
Pay Robert Downey Jr Whatever He Wants!
Robert Downey Jr obviously knows his stuff, and his statements - while confusing for fans - could be more about letting the studios know that they will have to make him a big offer to continue on as Iron Man.
Iron Man 3 hinted at a retirement for Tony Stark - what with his throwing his chest arc reactor into the sea - but it was less than a convincing one, especially as we know he will be back for at least two more Avengers movies. Could they work his retirement into [The Avengers 3](movie:738027), or do you think Tony Stark stepping down as Iron Man is momentous enough to need a whole movie to itself?
Retire Iron Man in The Avengers 3, or another Marvel movie!
If Marvel were to retire Iron Man in an Avengers movie, there are a few ways they could do it.
Iron Man has previously got so tired of having to deal with the chaos on earth that he has taken off into space, meeting up with the Guardians of the Galaxy, could this be an option for Guardians 2?
Alternatively, with Marvel seemingly building up to the Infinity Gauntlet in The Avengers 3, could Marvel work the Civil War into either [Captain America 3](movie:994409), or Iron Man 4, and have *both* Cap and Iron Man leave the Marvel Universe after taking it to the brink of self destruction?
Colin Farrell for Tony Stark, or who?
The final - and potentially most difficult - option for Marvel would be to simply reboot the character of Tony Stark (and Pepper Pots). But who could step in to replace Robert Downey Jr in the career changing role that he has preformed so well?
Some fans have suggested Colin Farrell, Jon Hamm or George Clooney - but would Iron Man fans accept the new Tony Stark, or would RDJ's bow out from Marvel simply mean it was time for someone else to lead The Avengers?
What do you think? Should Marvel make an Iron Man 4, even without Robert Downey Jr? Have your say below the line!