One of the biggest pains in deploying MS Office to OS X in a business or education environment is making sure that the serial number deploys too.

To do this, you need to also deploy the following files:

~/Library/Preferences/com.microsoft.autoupdate2.plist
~/Library/Preferences/com.microsoft.error_reporting.plist
~/Library/Preferences/com.microsoft.office.plist
~/Library/Preferences/com.microsoft.office.setupassistant.plist

Deploying these files will keep also keep the initial setup assistant from running upon first launch.