The folks at WordPress.org have released WordPress 3.0.1. This release addresses about 50 minor issues. You should upgrade your site immediately.
This maintenance release addresses about 50 minor issues. The testing many of you contributed prior to the release of 3.0 helped make it one of the best and most stable releases we’ve had.
Download 3.0.1 or update automatically from the Dashboard > Updates menu in your site’s admin area.
You can find more info regarding WordPress 3.0.1 at the WordPress Dev Blog.