On April 26, 2011, Version 3.1.2 was released to the public. Version 3.0.6 was also released for those who haven't updated to the 3.1 branch yet. It is an unannounced release.
This is a security update for all previous WordPress versions.
For version 3.0.6, the database version (db_version in wp_options) remained at 15477.
To download WordPress 3.0.6, visit http://wordpress.org/download/release-archive/.
For step-by-step instructions on installing and updating WordPress:
If you are new to WordPress, we recommend that you begin with the following:
wp-includes/version.php readme.html wp-admin/includes/update-core.php wp-admin/press-this.php