I recently got the question: "What is the risk of not migrating my Joomla 1.5 site to a newer version?".
That's a really good question, as the task of migrating to Joomla 2.5 can seem like a daunting one. Nonetheless, there are several compelling reasons to migrate your site from 1.5 when it reaches end-of-life in April 2012.
The Joomla Project announces the immediate availability of Joomla 1.5.11 [Vea]. This is a security release and users are strongly encouraged to upgrade immediately.
This release contains 26 bug fixes, two moderate-level security fixes and one low-level security fix. It has been 11 weeks since Joomla 1.5.10 was released on March 28, 2009. The Development Working Group's goal is to continue to provide regular, frequent updates to the Joomla community.