The last patch of the Joomla CMS, the 1.5.15 is available for download on Joomla.org :

• 1.5.15 Full Package in english
• The patch version from 1.5.14 to 1.5.15 in english

And the future major version of Joomla (the 1.6 version) is near to get out of the box !

Download, joomla