It’s a significant improvement over the free applescript when comparing the features. To download and see the features and screenshots of the new Outlook Mac Archive Tool go here It also supports archiving mail to the cloud (such as a GMail account) which keeps your archive safely backed up and accessible/searchable anywhere in the world. It is significantly more stable, featured and faster than the AppleScript.
I have now released a new tool for archiving in Outlook Mac 2011 which is a native Mac Application.
Out the box Microsoft Outlook for Mac 2011 has no equivalent tool to the auto archive functionality found in Outlook for Windows.