As this is a short term version, the Joomla! Project is recommending that those on version 2.5 stay there until version 3.5, the next Long Term Release, is made available. Only developers and web designers looking to be on the cutting edge of Joomla development need to upgrade or start using this new version. It is important to note that version 1.5 is getting very close to end of life for all support.

One other very important consideration when deciding whether or not to upgrade is the availability of third party templates and extensions. If you are using specific extensions for your Joomla setup, you must make sure that they have been made compatible with Joomla 3.0.

The inclusion of Twitter's Bootstrap framework has been one of the most anticipated changes to the new Joomla version. This change has the possibility of bringing a common look and feel to the Joomla User Experience, including the Administrator back end and third party extensions. The framework provides a common set of web elements, such as buttons, sliders and other form elements that can remove some of the learning curve with each new extension.

The other major feature that has received huge attention is the mobile readiness of the Joomla core. Out of the box Joomla will be able to scale for different devices like mobile phones. With the explosion of mobile web usage, this could be the most important advance in this round of Joomla development.

Other features include:

• A new front end template--Protostar-- built using Twitter Bootstrap.
• Updated accessible template called Beez3.
• A simplified 3-step installation process.
• PostgreSQL Driver. You will be able to run Joomla 3.0 sites using the PostgreSQL database.
• PHP Memcached Driver
• Use of JFeed for feed management rather than SimplePie
• Installation of language packages directly from the extension manager
• Guest user group present by default
• Saving blank articles allowed
• New administrator statistics module
• Update TinyMCE to version 3.5.6

For more information, visit Joomla.org