10. Sequel jitters

It all seems obvious now, but back in May last year, there were serious worries that Jon Favreau might not return, with worries that Marvel was trying to push for too much too soon.

“I haven't been hired to do it yet,” Favreau said in June 2008. “I know that Robert and I have talked a lot about what types of things we would like to do, and how to play into the strengths of what we discovered last time around.

“I look forward to rolling up my sleeves. Hopefully that won't be too long in coming.”

A lot of his resistance sounded like contract negotiation issues, but he was soon locked into a deal. Marvel has since shifted the dates of some of its other films around and Favreau is at work on Iron Man 2.

Even with Favreau and Downey back, and Tropic Thunder’s Justin Theroux on scripting duties, not everything went quite to plan.

Terrence Howard was roundly dumped from the sequel – he says because of money issues, insiders say because he was difficult to work with – and Sam Jackson nearly didn’t return as Nick Fury because of dosh problems.

Add to that the endless casting issues around Mickey Rourke (Sam Rockwell was a much easier catch as Justin Hammer) and the controversy over Emily Blunt taking, then dropping out of the role of super spy Black Widow, the path to the sequel hasn’t been smooth so far.

For now, however, things are on track…