Just moments ago, WordPress 3.0.2 was released to the public. This version is a mandatory security upgrade. According to the release notes:
This maintenance release fixes a moderate security issue that could allow a malicious Author-level user to gain further access to the site, addresses a handful of bugs, and provides some additional security enhancements.
It’s been awhile since we’ve seen one of these types of releases. However, thanks to automatic upgrades built in, upgrading is a pretty easy thing to do.