The fourth and (hopefully) final release candidate of Drupal 7 is now available for testing.
The Drupal team have announced a tentative release date of January 5th for final release of Drupal 7, so please get testing and make this final version the best it can be.
From the announcement:
Since the last release candidate a week ago, we have fixed numerous bugs, including bugs with PostgreSQL and a critical issue with the password upgrade path which corrupts password hashes. Affected sites' users will need to reset passwords after their second log-in. Sorry about that!
For the full list of changes, see the release notes.
Grab your copy and start testing today: http://ftp.drupal.org/files/projects/drupal-7.0-rc4.tar.gz