Version 2.5 is the second release made within the new six-month release cycle that started with the delivery of Joomla 1.6 in January 2011. Version 2.5 is also a long-term-support (LTS) release that will be supported for at
least 18 months. We have started testing all of our templates and extensions for 2.5 compatibility. Our latest template, Fetch, and latest extension, Quick Flip, have been testing in 2.5 and work well. We anticipate all other 1.7 ready templates and extensions will work too, but if you run into an issue, please let us know.
NOTE: Version 1.7 will reach end of life one month from today, on February 24, 2012. All users of version 1.7 should update to version 2.5.0 before that time. The update process is very simple, and complete instructions are available here. There are now easier and better ways of updating than FTPing the files.
Read more about Joomla 2.5 here.