Neill Blomkamp (District 9), Ben Stiller (Tropic Thunder), Shane Black (Kiss, Kiss, Bang, Bang), Peter Berg (The Rundown), Duncan Jones (Moon) and Paul Verhoeven (RoboCop) have all been short-listed to replace Favreau.
Duncan Jones--too serious. Ben Stiller--not serious enough. Of those listed here, I think Verhoeven would be my first choice (though it seems like he hasn't made a movie in quite a while). Starship Troopers was packed with futuristic combat action with a heavy dollop of mordant humour. That is, in many ways, how I would describe the first Iron Man movie. He'd be prime to recapture that sensibility.
I'm not entirely convinced by this explanation, omitting, as it does, any reference to Marvel interference or the Avengers stuff. Then again, RDJ exiting Cowboys and Aliens did come as a surprise and this may explain it.
I'm not, since I have no idea why people keep getting hung-up on the Avengers stuff, insisting that a brief interlude in a feature-length film is responsible for everything they perceive to be wrong about it (and I, for one, liked
Iron Man 2). I am, however, familiar with RDJr's reputation as being sometimes difficult to work with.
Fictitiously yours, Trent Roman