Joomla! 1.6 Beta 14 is out on November 15. The official announcement reports that between Beta 13 and 14 there are 69 issues have been fixed and 45 closed. There are only 5 issues in the way to the release of RC 1.
Next release will be on November 29, which will be either Beta 15 or Release Candidate 1. For now please download and test the current beta: http://joomlacode.org/gf/project/joomla/frs/?action=FrsReleaseBrowse&frs_package_id=5523
By the way, Joomla! 1.5.22 was released 2 weeks ago. It patches up a low priority security issue.
- Low Priority - Core - SQL Injection Information Disclosure Vulnerabilities: Inadequate filtering of request variables causes database errors.
Download links for Joomla! 1.5.22 can be found at its release announcement.