Joomla 3 has been released!
This is the latest version of my favourite Content Management System, and promises a whole raft of new features as detailed at http://www.joomla.org/3/
The general recommendation seems to be that if you have an existing Joomla 2.5 site that is working, stick with it. However, if you want to create a new site without a great need for extensions, then it's probably worth a look.
At the moment there aren't many extensions available, but this will definitely change as time moves on.