WordPress 3.0.1 has just been released. This version fixes 55 minor bugs, including a frequently reported export error and an incompatibility with PHP 5.0.5. The upgrade should be available for most of you from your Dashboard.
Download 3.0.1 from WordPress.org or update automatically from the Dashboard (Tools -> Upgrade) in your site’s admin area. If you encounter any trouble with the automated updater, try deactivating your plugins before reinitiating the update.