Just about anything can be hacked to work, however in most cases this requires a lot of time and motivation.
If you want to add blogging to your VB site I would suggest buying a license for VB blog, once downloaded you can be up and running in minutes and everything is integrated.
I will admit that the current version of VB Blog is a bit weak, however this is being worked on and a new release is due shortly.
Have a look at these pages:
http://www.vbulletin.com/features_blog.php
http://www.vbulletin.com/forum/showthread.php?t=274922