Who knows if the beta's will ever end, but honestly, you have to admit you're having fun testing right? Then you'll be pleased to know that beta 13 is now available.
Now snap on it and get this cleaned up so we can have an RC release will you? :P
Since the Joomla 1.6 beta 12 release on October 18, we have fixed approximately 71 issues in the tracker. We have closed an additional 28 tracker issues. At the present time, we have 13 issues that are blocking the release 1.6 Release Candidate 1.
More info: http://www.joomla.org