Hi all, I'm Sage. I've been a Wikipedian since 2005, and I've been thinking and talking with other Wikimedians about the gender gap since around early 2009, when the first results from that survey came out.
Right now, I work for the Wikimedia Foundation as part of the team working on the Wikipedia Ambassador Program, a project that makes connections between the Wikipedia community and academic experts and their students. One thing that's nice about this project is that when you're working with classes full of students who have been assigned to contribute to Wikipedia, the gender ratio is a lot closer to even. We're also finding, I think, that the people drawn to the Wikipedia Ambassador roles end up having less of a gender gap than Wikipedia contributors overall, and a lot of our Campus Ambassadors are people who totally new to the community.
Building off of Kat's ideas about Wikipedia attracting people with specific traits and not others, I think there's a lot of potential for attracting talented and enthusiastic people with different sets of traits if we do more to define specific roles they can step into. There's a ton of specialization within the community, but the gateway is pretty narrow: you have to like the part that comes right after you click [edit] on an article or a talk page enough to stick around. Once you've learned the ropes, you may find some other important part of the project (besides editing articles or commenting on them) is what keeps you interested, but if you don't like that first step enough, you'll never discover the other roles you could take on. So creating and drawing attention to other entry points into the community is an area where I see a lot of potential.
-Sage