I think he would more than qualify on net worth, but I'm not sure that he should be classified as a tech entrepreneur compared to the other people on the list. He made his original fortune in music, and Virgin Mobile is really just him licensing the Virgin brand to a bunch of independent pre-paid carriers. Also, I wouldn't classify an airline as high tech, and Virgin Galactic isn't really up and running yet.
Maybe that's not fair, though, considering Virgin Galactic really did seem to help kick start the privatization of space, at least in terms of popular press coverage.
Ah, I skipped right over "tech." Though I feel now that's kind of justified. A few these people started ISPs, admittedly those are about technology, but just barely. The technology was very rapidly commoditized, and then it became about business. I don't see any significant difference between that and Virgin Mobile.