Hmmm. I can't see them making Aquaman gay, he's WAY too into fishy women. Plus, no gay man would ever wear green tights and an orange scaled scoop-neck top swimming. (Not to mention all the years he had a magic, transforming water hand and all he made it into was a trident...)
Wonder Woman, maybe. She's pretty much been written as a lesbian since they retconned her into a funky kung-fu detective with no powers in the 70s. When's the last time you saw WW pursue a man who wasn't Supes, and therefore unattainable? Plus, you know, any woman who carries a rope with her at all times and wears a crown has SOME issues in the closet.
What about Power Girl? If she was gay her "HEY! LOOK! TITS!" costume might finally make some sense as a desperate attempt to appear straight. I know several lesbians who went through a definite "mega-slutty" phase as a beard.
Maybe Green Lantern? Yeah, he's hooked up with his share of ladies, but he places an awful lot of focus on jewelry for not being Italian.
Martian Manhunter? He wears a speedo and suspenders (which essentially makes him Mr. March in a hot firemen calendar, and those are NOT marketed to women). Plus he calls himself "Manhunter" for God's sake. Might as well just call himself "Carl Cockhunter."
Who says it's a hero? Maybe a villain is going to come out. Lex Luthor has gone through some major prissy/bitchy phases in his life, plus, you know, he DID choose to make his battlesuit iridescent green and purple...
Bizzarro? If he is the opposite of Supes, me MUST be gay, since Supes is so straightlaced he probably thinks "People" magazine is porn and Wal*Mart bargain-bin underwear is lingerie. (Superman can not possibly be gay since he has x-ray vision and has never been caught crotch-scanning Jimmy Olsen, even to just check and see if the carpet matches the drapes.)
What about the Joker? He is, from a certain point of view, nothing more than a tragically misguided transvestite who knows nothing about make-up. He also wears an AWFUL lot of purple for a white guy. Plus, now that I think about it, what straight man would not have boned Harley Quinn to within an inch of his life five minutes after seeing her?
Who else could it be? Robin? That old outfit was HIGHLY suspicious.
Ras? He does tend to wear dresses and occasionally thrust himself into Lazarus's pit...
Penguin? He hangs out with birds in nightclubs and his nose is practically a dildo. (But that last could be an argument for his heterosexuality, too, I suppose.)