We have had some 20 ThoughtWorks staff work on it over the years, and as many non-ThoughtWorks folks, but principal amongst developers is Jason Huggins who started "Selenium Core" in 2004 when he was at ThoughtWorks.
To herald this wonderful moment, we also have a new documentation set, that is a 10x improvement over the previous set, and has been almost entirely contributed by the user community.
Going forward the Selenium team thinks it will get busy with 1.0.x and 1.x releases, not withstanding the effort already in place for Selenium 2.0 (nee WebDriver) also by a former ThoughtWorker, Simon Stewart.
There is a Meetup event in play right now. Watch out for Twitter tags #sfse and more formal event snapshots and write-ups.