Users won't have to transition to 3.0 version yet, if there is no need to upgrade and any new projects that users may design can use the latest release. Version 1.5 is officially out of support with this latest release and current version 2.5.x will be supported until Spring 2014. The latest version runs on PHP 5.3.1+ and MySQL 5.1+. Users who are transitioning to the latest release are recommended to test the plug-ins and components for compatibility with version 3.0 before the transition.
The big question that arises when a business or individuals start a blog or a website using a CMS system is weather to choose Joomla or Wordpress. We ourselves are on Joomla CMS as opposed to WordPress for a simple reason that we could find more plugins and ready made components that met our requirements in Joomla comparative to other CMS systems. While WordPress comes with simplicity at its best for bloggers and small business Joomla offers that variety. Admittedly transition from version to version is not as simple or seamless in Joomla compared to WordPress.
The latest features include a new responsive, mobile device friendly administrator template and interface along with support for PostgreSQL Database, PHP Memcached Driver and use of JFeed for feed management than SimplePie. Joomla now has Guest user group by default and allows to save blank articles which wasn't the case in earlier versions. The administrator has a new statistics module with extensive work on code style standardisation and consistency. Another big frustration that has been taken out is by letting the SEF plug-in add the canonical url to the head.
Joomla claims the future to 3.0 is in 6 months, Joomla 3.1 will be released however this time it's a one-click upgrade and will be backward compatible. If you are on Joomla 3.0, you will need to upgrade to 3.1 at that time using the one-click upgrader. If you’re still on Joomla 2.5, you can continue to wait until Joomla 3.5 and still get a direct upgrade. Sounds like a plan.