Not only is he gay, he's openly gay and apparently gets a make-out session (with, yes, a guy because I knew you'd ask) in either the first or one of the first episodes. It's not Torchwood, but hell, I'll take it.
This isn't just because I like watching boys making out. Because I do. This is because it's always a major victory when mainstream or near-mainstream television has a character who is a) homosexual, b) a male and, c) has the homosexual male actually getting some. Most of the time the gay character is shown off to the clamor of 'aren't we inclusive!' bells and whistles, and then gets to show he's in a relationship--when he gets to have a relationship--by sitting near to another male and pining. Lesbians might get to kiss a little, unless they're written by Joss Whedon. But writing lesbians is easy. Women liking other women is acceptable. It's cute. It doesn't threaten the ideals of patriarchal manhood. If a show wants to look like it's hip it'll just throw in a lesbian for a few episodes--wow! how edgy!--and then vanish her again.
Pay-per-view is obviously another story, but even then I can't think of an openly gay character on Showtime since Queer as Folk went off the air. There's a gay guy in The L Word, but his plotline is not exactly the point, for obvious reasons. There is also a transgendered man in a woman's body, but he's heterosexual as far as I can recall.
I'll admit that I don't watch a huge amount of television, though, so I might be missing a hotbed of inclusiveness somewhere. If so, I'd be happy to hear about it.
So, long story short, this is really, really cool. Cooler still would be if one of the main characters like Apollo or Helo would be shown to bat for both teams. But as usual with the grand, grand majority of US television, the idea of a leading man going for other men is too terrifying to contemplate. So this will have to do.
At least BSG has a gay character, unlike my used-to-be-favourite Stargate: Atlantis, where the producers and writers seem to be constantly falling all over themselves to show how very, very attracted to women all their male characters are. They have had a main character imply that he's not homophobic, which is nice, but God forbid they'd have, say, the technician guy Chuck making out with another Canadian airman in the control room (he's Canadian--it's allowed), or maybe two of the female civilians holding hands in the background. I won't even mention the main characters, because despite the chemistry between all the male leads, it'd naturally be out of the question. Gay men simply can't save the universe. Unless they're Jack Harkness.
But like I said, I'll take what I can get. As usual, science-fiction seems to be paving the way for general acceptance of the taboo. That said, I won't consider it a true victory until the Sci-Fi channel launches a show on television, rather than the still-ignorable internet, with a homosexual character in the regular cast who stays in the regular cast (a man and a woman would be nice, thank you). And who then actually gets to make out once in awhile.
More non-white and female leading characters would be excellent, too. But I'm not holding my breath about that one, either.
Still, this is a fine start. Good for them.