Of course your WordPress Dashboard can tell you the same thing- but, a few minor fixes and WP is at 2.2.2

WordPress › Blog » WordPress 2.2.2 and 2.0.11
Today we have two security-related releases available for both users of our main 2.2 branch and the legacy 2.0 branch. As these releases include only security and minor bugfixes they should not cause any plugin or theme compatibility issues, so you have no good excuse not to upgrade.

This weekend, we also upgraded to PHP 5- and only had a few things break. Mostly due to older plugins. We’ll give a full report once we’ve tracked all 100 or so installs that we have of WP.