Joomla 2.5 is going to be dead soon, on December 10 the last mantainance release will be released.
With the version 2.5.28 that will be the latest release for this branch, Joomla 2.5 won't be updated or mantained anymore, this means that also if security bugs will be discovered they won't be fixed leaving your site vulnerable.

For this reason the Joomla! team encourage all users to update to the latest Joomla 3 all sites owned.
Our extensions are all distributed both for Joomla 2.5 and Joomla 3, so if you upgrade to Joomla 3 you need only to download the corresponding version from your purchased products area.

More info at this official link: http://developer.joomla.org/news/599-joomla-extension-developers-what-resources-do-you-need-for-the-final-release-of-2-5.html