I've helped recently to unfork the Bluebeach theme (the theme used on Drupal.org and subsites) which was used with different code on drupal.org and groups.drupal.org. So now both sites can use the same source code for their theming. I've also ported the changes to the Drupal 6 port of the theme which was done by Earl Miles earlier, based on the Drupal 5 version. These were all in anticipation of doing upgrades of drupal.org and subsites with the existing theme before going to the next step with Mark Boulton's redesign.