I was fascinated to read about the cancellation of the British Ruby conference due to the arguments that the speaker lineup lacked diversity. Other people have their own opinions on why we have this problem and what we should do about it. I've spent a lot of my career as a hiring manager, trying to walk the fine line between encouraging diversity and slipping into tokenism; I've also had to be as impartial as possible in selecting conference talks (full disclosure: I'm on the RSA 2013 committee).
As someone who has a chromosome allocation that has traditionally been in short supply in IT, I'm used to being the only one of my kind in the room. If that makes me a unicorn from time to time, there's not much I can do about it, short of leaving the room, and that kind of defeats the purpose of my being there in the first place, which is simply to learn from and contribute to whatever is going on. If I've been exceptionalised, it wasn't such that I could detect it, but I don't know what discussions are ever held behind the scenes.
But here's the thing, the most important thing: What we see every day is what we expect.
Our brains are hardwired that way, so that we spend less processing time trying to re-analyze and make predictions about stuff that we've experienced before. It goes on without our realizing it, and you can sometimes tell it's happening when you find yourself paying more attention to something than you usually do; it means that something is different from what your brain was used to. We expect humans to be walking on two legs, and so we notice anyone we see on crutches or in wheelchairs. We are used to women with hair on their heads, so a woman with visible hair loss receives a lot of attention (as I did in the middle of chemo when I visited my kids' school playground). This is natural.
So if we want to hack our brains, we have to be conscious about it, and put some effort into changing our subconscious expectations of the way things ought to be. This is why I applaud conference organizers such as Chuck Hardy who work on soliciting paper submissions (and more than one B-Sides conference does this too; I've volunteered to be a speaker mentor for London 2013). Reaching out to anyone who is different from yourself -- and helping them along if necessary so that nobody can complain about quality -- is what we need to do to change our experience, and therefore our expectations, of who is seen onstage.
I don't know whether I've ever been invited to speak simply on account of being female, but if it happens, I'm okay with it. Haters gonna hate, and they probably won't change their minds on why I was selected just because I gave a pretty good talk. But at least I have a chance with the rest of the audience: to change their experience regardless of whether I'm a quality presenter (we're all used to seeing bad male speakers, aren't we? Why shouldn't I be allowed the same opportunity to fail?).
So if you want me as your unicorn, I'll take one for the team. If it means opening up the door a little wider in the future for other people who look different, then I still think it's worth doing.