In my own research on WordPress stats, 25% of all websites are published with WordPress, though this is based upon the statistic that more than half of these are on WordPress.com, where people come and go and set up test sites on a regular basis and abandon them, so Matt’s number may represent a more accurate number of active sites.
Aaron spoke at my last WordPress class at Clark College and is the founder of WordCamp Portland (PDX), an annual WordPress event in Portland.
I highly recommend attendance.
For those already familiar with the code, WordPress Themes, and Plugins, a second meeting will be Tuesday, October 16 at 6:30PM at the US Bancorps Bldg, and be focused totally on the code and developer issues. See Peer Code Review for more details.