"...yet I don't see it in their blog collection..."
Here's the point: Unlike blogger or userland, which host tens or hundreds of thousands of blogs, oreillynet.com's blog collection consists of internal O'Reilly people, authors, and some outsiders who've asked if we could host their blogs. If they ask (nicely) and there's some relevance to the kind of content we cover, others can be included, but we don't seek out bloggers of either sex. Maybe you're right and we should be seeking out interesting bloggers and asking them to move to O'Reilly. But that seems a bit silly. If these people already have their own blogs, why would they want to move to our site? This is a distributed medium after all. Many of our good friends (part of the group that critics seem to think of as part of our "blog mafia") like Cory Doctorow or Doc Searls have their blogs elsewhere, and we like to read them wherever we find them. What's more, most of the oreillynet bloggers are (like me) only occasional bloggers, which is why we aggregate them into a combined flow. If you're a continuous blogger, you more likely want to have your own branded blog.
I find myself really puzzled by this thread. We don't publish all the great authors either, yet no one accuses us of excluding the authors who choose to write for Addison-Wesley, or Peachpit, or the late lamented Wrox. Most of our books are written by men too, as the computer industry is a male-dominated industry, yet no one complains that we're sexist because we don't have more female authors. We don't make the sex of our contributors a litmus test, either for or against, and neither should the rest of you. We choose our authors and speakers on the strength of their ideas and their willingness to work with us. (We choose conference talks from those that are submitted to our RFP; only keynotes are usually invited talks.)
I'll stand up to any company in the computer industry about creating opportunities for women. O'Reilly's staff is fairly evenly balanced between men and women. Three of the six top managers who report to me (my COO, my CFO, and my Associate Publisher) are women. And that's something you won't see in many companies in any industry, let alone the male-dominated computer industry.
I also find the implication that we're somehow excluding women from our conferences to be rather bizarre. Yes, the number of women at the Emerging Technology Conference was dwarfed by the number of men -- but there were far more women than you'll find at almost any other technology conference. That's a comment on the state of our industry; it doesn't say anything about O'Reilly.