Over the next few days, there are going to be a lot of posts that say "not so at my table". It seems to be how these threads come together.
From personal experience, there is usually a slight majority of males at my table, but nothing to really get worried about. Both of my female players are strikers (both are the same class, in fact!) and neither is particularly mechanically minded. But both are vital to the party's success, and I don't think either has ever played (or been pushed into) a support role.
I think the bigger problem with "women in gaming" has been addressed already, and the answer is simple: male gamers. There is a gaming store that usually has a game going on it. It used to be a hobby of my girlfriend at the time (who was not into gaming) to go into that store with me, because she enjoyed becoming the centre of attention of every male in the room. There are, unfortunately, a lot of "Gamer geeks" who can be a little odd. And this can unsettle women at the table.
I've had gamers who had never met the rest of the table sit down, start playing, and instantly assume everyone at the table knew how to play the game... except my female players (and he would give them "advice", even though it wasn't asked for). This is one of the deterrants right there.
And then there are GMs who assume that women players, on the basis of their gender alone, want certain things in the game. These GMs often try to change their game style to accomodate their perceptions on what the women want in a game - usually without bothering to ask the female player. Many of us have seen it - the whole "women PCs inevitably will get involved in a romance because the GM thinks that's what the female wants" fiasco.
My two female players? Neither wants to be the centre of attention, but both want to be very vital to the group's success. One likes being able to "think outside the box" and come up with clever solutions to a group's problems, while the other likes being the queen of ass-kicking. Both do their jobs very, very well.
If I showed you how our combats played out, removing character names and genders from the examples, you wouldn't be able to figure out which PC was played by a woman and which by a male. And this would be the case at many tables. So why assume that women want anything different then men?
And, finally - why does it matter? If 80% of gamers are men, does that matter? Why do we need to recruit more women? We're not into marketing or anything - it's just a game. And some things appeal more to one gender than another (how many men are into crafts? Or horseback riding? Or baking? All of those are hobbies that have both genders involved... but tend to have more women). So why is this even an issue?