Full-disclosure: I am both a woman and a Grooveshark employee. Not just employee - Developer.
I read your blog post, and you make some very good points. I feel much the same about the industry as a whole, and became especially sensitive to it after attending FOWA Miami last year, and seeing the vast, vast difference in the number of women in attendance versus the number of men. At the after parties, I walked up to every woman I saw and asked them if they were programmers. I didn't find a a single one. They were all in marketing or design.
But here at Grooveshark? Yeah, so the "that's what she said" joke on our 404 page is inappropriate. But it's still pretty damn funny. Maybe I'm biased. I've heard "that's what he said" jokes thrown about the office as well. As a woman, I'm certainly in the minority of employees here at Grooveshark. But I am absolutely not dumped into any sort of Illustrator ghetto. In fact, I'm the lead ActionScript developer here. The actual Grooveshark application you use every day? Until the redesign, that was all me. It's gotten too large to be maintained by a single dev anymore, but I'm still the one who designs and writes all the application's architecture. I am not sexualized (at least no more than any of the men are) or vilified here. I am a valuable part of our team.
So yes, our industry has a serious problem. But don't think Grooveshark (or our 404 page) seriously contributes to it.