Anyone that has done a lot of work in Drupal knows what a complete pain it is to upgrade from Drupal 5 to Drupal 6.  The change was dramatic, and many vital Drupal 5 modules still haven’t been upgraded to work in Drupal 6.  For many sites, going from Drupal 5 to Drupal 6 isn’t so much an upgrade as a rebuild. 

Given this, it is sort of amusing that Drupal’s flagship website, www.drupal.org, is down today for maintenance as they upgrade from Drupal 5 to Drupal 6 a full year after the release of Drupal 6.  I guess it really is as hard of an upgrade as it seems.