This is getting a lot of hate, and I understand why. I mean sure, it seems like a stunt, and it might very well serve as that too.
But the thing is, I'm glad they're doing this. I think it's smart.
Back when these characters were made, you just couldn't publish a gay superhero. It wouldn't happen. Now these characters are iconic and the most well known of DC's universe. What better time to make a change like this than a reboot?
Sure, sure, I know people are saying "Why not make a new character?" but... Well, first of all they have. Bunker in the new Teen Titans is gay, and the DC assimilated Stormwatch run is doing a very good job on the Apollo/Midnighter romance. Batwoman is sticking around as a lesbian superhero.
Secondly, making a new character who is gay just isn't going to change much. They'll probably just sink into the depths of obscurity. It wouldn't change how we think of homosexuality in comic books.
I think it's a great idea to take an established character who is an iconic part of DC and make them gay. It's a slight change, and if DC handles it like Paul Cornell or Scott Lobdell did with their gay characters, then it should be easy to pull it off in a way that's respectful and, well... Classy.
Also, I doubt it's Aquaman, since his wife is already in his book.
Honestly I think Batman fits this role best. He just can't seem to settle and has meaningless uncommitted over-compensating women sex. Who knows how much of it is just his Bruce Wayne persona?
I'd like it to be Flash as I'm already collecting that book, but he seems hung up on Patty Spivot and Iris West.
A gay Wonder Woman would be cool. I'd like that best, probably. Then again, I don't see why she'd leave Paradise Island if she was ;D