This is a summary of what the developers are working since Dries has opened the new developer tree on Apr 7, 2005. I presume that you are familiar with Drupal 4.6, I'll list only the major news.
For the last several weeks the Drupal documentation team has been working to organize and create documentation. We have come up with several documentation handbooks that we believe will best meet your needs.
The folks over at Good Basic have been doing a fine job of converting some of the brilliant templates available for various other CMS packages into Drupal templates.