It just wouldn’t be a superhero movie without some talk of a spin-off ahead of the actual release.
Slash got some words from Joe Johnston and the screenwriters of CAPTAIN AMERICA: THE FIRST AVENGER about what directions a sequel could take - - and where they’d want to take it. Basically confirming what I’ve suspected ever since Sebastian Stan’s casting announcement mentioned appearances in five to six pictures, Johnston’s expressed interest in doing a movie about the Winter Soldier.
I actually got to see CAPTAIN AMERICA last week (and it was phenomenal. Seriously. Best Marvel movie yet) and, without saying more than needs to be said, this twist would be workable. I think it's more workable is to have Bucky show up to bedevil Steve in a proper CAP sequel first, and then let that be the catalyst for a Winter Soldier spin-off.
And speaking of spin-offs for villains, Johnston also said that he’s been bugging George Lucas about doing a Boba Fett solo movie. Even though Johnston was one of the creators of Boba Fett while he was working at ILM, I honestly don’t see such a project going anywhere past idle discussion. At most, I could see it develop into Johnston directing some Fett-focussed episodes of the live-action STAR WARS series (whenever it comes out.)