I had written in the post describing 2.2’s arrival that there was no mention, and it wasn’t clear from the WordPress bug tracker whether 2.2 included any security updates.
The recently married Mark has left us a comment saying WordPress 2.2 Getz includes some security fixes. As with all upgrades that include security fixes, you are encouraged to upgrade to this release as soon as you can. You don’t want any holes, big or small in your WordPress blog. The reason I upgraded WordLog and resumed posting is because someone used a hole in the old, un-upgraded version to upload copies of movies, including Hannibal Returns to my VPS. Yes, it can get that ugly! So upgrade now.