Content Management Systems: Drupal 7 vs Joomla! 1.6
Improvements to Joomla! 1.6 include a combined Section and Category Manager, as well as a new Access Control system which enables admins to create custom user groups, and control who sees what via access levels and permissions.
Compare this to Drupal's core taxonomy handling and user role/permission system, and Joomla! still doesn't hold up. Drupal wins due to its ability to finitely control, allowing admins to apply multiple categories and providing granular control over custom permissions.