Are Thor and Captain America strong enough for sequels?

If there’s one thing that’s clear about this summer’s blockbuster movie lineup, it’s that superhero movies have gone from terrible homages as they’ve been in recent years to full-blown blockbusters that any geek can enjoy (as well as non-geeks alike). The Avengers and The Amazing Spiderman have done exceptionally well and The Dark Knight Rises is right around the corner.

Two movies that are getting some buzz out of Comic-Con are Captain America: The Winter Soldier, due out in 2014, and Thor: The Dark World, due out in 2013. Personally speaking, Cap was my favorite of the Avengers and I felt that the first move did a great job at introducing his character, but is he really strong enough to carry a stand-alone sequel? Is Thor, who was an occasional player for the Avengers, able to be Mr Sequel? Marvel seems to think so and they’re going to bet big on it with shooting starting in January, 2013.

Ironman is definitely strong enough for a third installment after strong box-office showings with the first two, bringing in $585,174,222 and $623,933,331 respectively. Captain America ($368,608,363) and Thor ($449,326,618) did very well, too, but are they poised to do better with the sequel the way Ironman did? Are they making these movies simply because they can or is there real value that can come from them?

The real question: is the studio milking this for every potential penny that they can before the popularity of the series goes kaput?