I’ve just tested Drupal 6.0 beta 1 and it’s again a good release.
The improved i18n system is good, the trigger/action modules will finally allow custom automated tasks without needing 10 different modules (hope it has good support for token module), and the new teaser system is elegant.
Having said that, it does feel this version doesn’t have such major changes as previous ones. Some of the nice things like openID and status update are just an inclusion into core. I hope the many revised APIs will spring many new useful modules, otherwise it feels like too little gain for another round of contribs porting.