Putting together an official "Release" of Docutils is a significant effort, so it isn't done that often. In the meantime, the CVS snapshots always contain the latest code and documentation, usually updated within an hour of changes being committed to the repository, and usually bug-free:
To keep up to date on the latest developments, download fresh copies of the snapshots regularly. New functionality is being added weekly, sometimes daily. (There's also the CVS repository, and a mailing list for CVS messages. See the web site [address above] or spec/notes.txt for details.)