It is strongly recomended that you update your site right now! There are no new features in these installments only bugfixes.

Drupal 4.7.11 and 5.6 are now available for download. These are maintenance releases that fix problems reported using the bug tracking system, as well as security vulnerabilities.

Upgrading your existing Drupal sites is strongly recommended.

See download links here: http://drupal.org/drupal-5.6