Sonicwall Firmware 22.214.171.124-27o was released on 31st December and has some interesting new features , Primarily - real time application control.
APPLICATION INTELLIGENCE,CONTROL & VISUALISATION OVERVIEW
The application filtering feature has also been incorporated into the content filtering service. So policies can be defined by application as well as content and applied to groups, and use schedules eg. relax rules for lunch.
Here is a PDF GUIDE for using the Sonicwall Content Filtering Service for version 5.8 firmware and upwards.
Finally here is a link which will allow you to browse the gui of a demo sonicwall appliance with the latest firmware.