Superhero movies these days attract some of the best directors in the biz, and Clint Eastwood is fresh of the success of American Sniper, which was awesome. He's also just a legend overall and could probably nail a superhero movie - I specifically could see him crushing it with something big like Superman.
He recently talked about the possibility of directing a superhero movie at CinemaCon:
"Not now, I don't think. I read comic books when I was a kid, I don't read them now. I prefer adult oriented stuff. I mean that in the PG-13 or R sense, but that's as far as it goes."
Not sure if that makes sense. I don't think superhero movies necessarily have to be aimed at kids. But, yeah, it doesn't sound like Eastwood is all that excited to crank out a superhero blockbuster.
Shucks... well, at least we still have The Good, The Bad, and The Ugly to remind us of the greatness that is Clint.