The Joomla! community is pleased to announce the immediate availability of Joomla! 1.5.1 [Seenu]. Since the stable release of Joomla! 1.5 we have seen huge numbers of downloads which has helped to push the total number of downloads to over 3 million in less than a year.
We have found in one of the new features of Joomla! 1.5, an XML-RPC Blogger API plugin, a high priority security vulnerability. While this feature is disabled by default on every Joomla! 1.5 install and would have to be manually enabled for the vulnerability to exist, we strongly recommend that all Joomla! 1.5 users upgrade to Joomla! 1.5.1.
Thanks to the work done by both the Joomla! Bug Squad as well as the Development Team , not only has this vulnerability been patched but so have several other smaller issues.
It is with great pride that the Joomla! community announces to the world the immediate availability of Joomla! 1.5 Stable [Khepri]. As a community of contributors, we have been through celebrations and tribulations. We have had fun, and we have worked hard. We have learned from and helped one another. What started two and a half years ago with a letter to the community has grown into a great opportunity for both the Joomla! project and community to benefit from these efforts and to consider our future.
Site Administrators - Simplicity & Control
At first glance, you will appreciate user interface improvements. The Joomla! 1.5 Administrator is more refined and the main menu simplified. The global configuration was substantially reworked for simpler presentation and greater control.  An important improvement for our international community is having Joomla!'s entire Administrator available in one's own language using language packs made available at joomlacode.org.
Joomla! administrators will find a number of improvements in ease of site management. A single installer is available for all extension types, including languages.  The media manager is improved visually and functionally. Images, documents, presentations, and more, can now be stored. Other improvements include multi-delete capability, batch file uploads, and an ability to view media in icon and list formats.