Up until recently, DC's policy was to introduce new characters and have them already be homosexual, as opposed to their standard policy of pretending Obsidian was just, like, totally too busy for dates and just wanted to keep his private life private, OK? Also, Maggie Sawyer was kinda sorta "roommates" with another woman, but yeah.
To be fair, the retconning has had upsides and downsides. Rene Montoya was such a disaster (mostly because of the horrible, horrible way that people who really should have known better were writing her) that they actually just freaking killed her off. Meanwhile, when they introduced a new gay character in her own book, after hemming and hawing about it for what felt like decades, that book turned out to be "Batwoman", one of the best written and flat-out beautiful books of the New 52.
And now, according to Dan DiDio, they're going to out a "prominent" character. Uh, yeah, Dan. Sure, whatever. We want to believe this is true...but this is DC. "Prominent" probably means "b-lister". There's no way Superman is coming out of the closet. Here are some of the "prominent" characters we suspect might be getting an outing.
This we could see actually working very well: after all, part of what makes "Supergirl" a great book is the fact that it's about a young woman struggling to define herself, something the underrated Mike Johnston has done a great job of making a quiet underlying theme to the book. Struggling with her sexuality would add a nice dimension, especially if it's handled with some sensitivity.
Again, they've got a prime opportunity: "Earth 2" is rebooting the entire JSA in the modern era, and honestly at this point it'd be a little weird if one of the JSA's members didn't turn out to be gay. And they're definitely prominent in that the company was built off these Golden Age characters.
Similarly, James Robinson has never been shy about discussing sexuality; in "Starman", Mikaal was openly bisexual, and Opal City had its share of minor gay characters.
You in the back, keep the cracks about his outfit to yourself: there are more awful costumes from that time period.
No, we're guessing Vibe is going to be gay for a simple reason: DC is suddenly all about bringing him back, when he's possibly one of the most loathed characters they've ever conceived of. He's not just featured in their Free Comic Book Day issue: he's actually getting his own deliberately cheesy short in "DC Nation" on Cartoon Network. And he's being put into Justice League, DC's most successful, and least diverse, book.
This is pretty straightforward DC: they love to play it safe on this stuff. Firestorm is big enough to be a big deal, but minor enough that they can quietly bury it if the book bombs. So Ronnie or Jason turning out to be gay is a likelihood for them. If it's written well, we'd love to see it.
Just rebooted, newly introduced, and no real romantic history. We're fifty-fifty on this one: it'd be easy to pull off, but DC would, not unreasonably, catch some flack for introducing a character so similar to Batwoman.
The only downside to this one is that their book is turfed after issue 12. But it's practically canon already, so DC should just pull the trigger.
Again, close ties with Batman, but not so close that it might "alter the brand" (we hate typing words like that, but this is how accountants think). And it would give Bunker somebody to actually, you know, have a romantic relationship with who wasn't basically Terry Long all over again.
It would also make this panel incredibly awkward, which is why we chose it.
Again, this is a horribly cynical choice, but let's face it: it's the kind of choice DC will gleefully make.
DC would never have the chutzpah to make Guy Gardner gay, and having an officially gay Lantern who isn't some sort of alien copout would do wonders for one of the flagship books. In addition, considering that Stewart is a former Marine, expert sniper, and arguably more powerful than Hal Jordan, he'd be a good choice.
This is one of the more likely ones, but frankly, DC, let's go the opposite direction. We know this has been unofficial canon for years, and only recently, thanks to Harley Quinn, have we seen it reversed, but at this point in human history, depicting a homosexual as a completely psychotic homicidal maniac is...how do we put this...absolutely awful.
So, let's ditch this. The Joker is supposedly dead right now, but we all know he's coming back. This is a reboot, so, let's retcon him as straight and never speak of it again, shall we?