Eddie Redmayne is apparently waiting for the call, because he wants to play the Riddler.
There have been so many films in the last decade or so that it feels like every corner has already been tapped.
However, the truth is that there will always be a need for new actors to play Marvel and DC and other superheroes and there will always be actors available to play them.
At this point it seems like pretty much all of Hollywood has been cast to play either a hero or a villain in a comic book superhero movie.