We've recently been digging around into the latest version of Drupal; version 6. We're particulary impressed with the new AJAX-driven interface; lots of slick drag-and-drop functionality. The 'Actions' are also very impressive, and a lot of the modules from previous versions have been included in the core. The e-commerce admittedly leaves a bit to be desired in terms of performance, but Drupal 6 is looking very stable and we're excited to roll it out for some of our new clients in the very near future.