One thing that I strongly suggest people interested in this issue to (and I'm not the first person to suggest this, much smarter people have preceded me) is make award nominations. If there's a story you like that you think might get overlooked and you're a SFWA member, nominate it for a Nebula, for example. I'm not saying only nominate stuff by women -- but if people want to see more stuff by women on ballots or ToCs, they may want to start exercising their own power to influence that.