Fortunately, since 1996, the task of getting Jerry Pournelle's job has gotten much, much easer: start a blog, write on a schedule, promote your content, and become popular. Then pitch the blog (and it's topic) to the publishing venture of your choice.
Pournelle is the guy who said, in the 80s, "By 2000, anybody will be able to get the answer to any question (for which there's a known answer)." (Possibly a paraphrase; I stopped looking when I found a quote).
Anyone else notice how this kind of overlaps with the recent Malcolm Gladwell book's thesis?