Honestly this plugin is now useless. Errors galore and hasn't been updated in over 6 months. Maybe the developer is waiting for vbulletin 4.0?
A more useful plugin would be a wordpress plugin that integrates seamlessly with vbulletin. Using wordpress as the front end for CMS, and pulling in vbulletin avatar information where wordpress avatars on the CMS side. Also, cookies so people don't have to login twice, and ability to map different levels of users.
Basically, we all need the REVERSE of this plugin. Now, that would be something a LOT of people would pay for!!!
Look at
http://www.jfusion.org they do this for joomla/vbulletin as a master control bridge. Why not make one for wordpress to vbulletin?
Any developers how difficult is this?