CMS Upgrades - Why Bother

If your website runs on a content management system (CMS), such as Wordpress, Joomla!, Drupal, MODX or Concrete5 (there are loads to choose from CMS Matrix), when was the last time you updated the version you're running on? Did you even know that there were newer versions, or do you simply feel that your site is running just fine as it is, why go to the bother? Let's take a look at why you should make the upgrade.