I haven't seen Bomer in much but the guy definitely has the right look to play Bruce Wayne. If he's a good actor who cares if he's gay? That would be like getting all worked up because he's a vegan and I like eating meat. It has absolutely no bearing on how he will perform the part.
I could care less if he is gay. For me my choices to play Batman are between Bomer and Caveizel (I think I butchered the spelling).
My important criteria is how they look and act. Thier sexuality is none of my business.