Try Real Preview for Joomla 2.5 right now. You'll wonder how you lived without Real Preview and version control for articles in Joomla!

compat 25 
Frontend: DEMO
username: demo
password: demo

Please note: The demo is a default joomla installation of 1.5.26 / 12.5 stable and is rebuilt every 15 minutes so you won't have too long to write long articles, but you will be able to demo and see how real preview for Joomla works with draft versions and real time previews of unpubished items. Various components are deactivated to prevent abuse.