Iron Man 4 Wishlist: 10 Things Fans Demand
4. The Formation Of The Illuminati
As an alternative to killing Stark, it would be pretty smart to move him more into the advisory role he's already started to take on increasingly. The best answer to that sort of approach is to introduce The Illuminati - the council of super-intellects who form a sort of super-watch including Stark and Doctor Strange (as well as Mr Fantastic, Black Bolt and Namor).
And using them to perhaps deal with the Hulk situation would be a great story to focus on in Iron Man 4.
That would allow him to stay in the MCU, but in a slightly reduced role and without front-line active duty necessarily, meaning Marvel could still count on his charisma, but wouldn't have to give him more stand-alones after 4.
Will It Happen?
At this stage it looks difficult: there may be rumours that Marvel want to work with Fox on a deal for the Fantastic Four, but nothing is set in stone at all, and both Namor and Black Bolt are unavailable for various reasons: Namor because he's not involved yet, Black Bolt because he's heading to TV...
But it would be great all the same, and if they can come up with a way of doing it, it would answer both the need to "end" Tony Stark's stand-alones and introduce a new lucrative property for Marvel.