A few years ago Joel Edgerton wasn't well-known outside of Australia, but these days it's hard to find a superhero movie that doesn't have the actor rumored to be in consideration. To this point, however, he has yet to sign on the dotted line.
It's Edgerton's ability to build intriguing characters out of lacking scripts (see: The Thing) that holds the most promise - a skill capitalized on for Zero Dark Thirty (2012), using the actor's brief role for most of their advertising.
With a standout lead performance in Warrior (2011) and upcoming roles alongside Natalie Portman and Michael Fassbender in Jane Got a Gun (2013), and Leo DiCaprio in The Great Gatsby (2013), Edgerton's star is definitely on the rise.
If the filmmakers are looking to get the attention of discriminating moviegoers, not just mass audiences, Edgerton would fit the bill. Provided he doesn't sign with Marvel first.