Re: Downey's last?
RDJ has turned Iron Man into a regular superhero, who might not even of been known of by non comic fans into a huge mainstream character with worldwide appeal. Iron Man is not one of the top Marvel superheroes among Spider-Man, Wolverine and Hulk. RDJ pretty much did all of this with his performance as Tony Stark. They even hired an actor on the The Avengers: EMH to sound exactly like RDJ.
I really don't see how they would continue if they don't renew his contract after IM3. It's quite obvious they're trying to get out as many films with RDJ as they can. 2 years in between IM1 and IM2, 2 years inbetween IM2 and The Avengers and only 1 year in between The Avengers and IM3. I really don't want even to think of a time where RDJ isn't Tony Stark.
He obviously loves the character, the fans and the spotlight. This role rejuvenated his career and I think he'll want to play the character as long as he can. He's 46 and he could play this role until early-mid 50's to be quite honest. He looks like he's in his 30s, and 50 isn't really old anymore.
"In my book, experience outranks everything."