Since about the start off 2011, there is a new Joomla! release available: version 1.6. Not wanting to be the first to find all the errors and waiting for some of the components to work with version 1.6, the second half of 2011 the site will be upgraded! Just to test out for other websites too.
Biggest issue will probably be the template used. But hey, every now and then a new template is not bad.