This vBulletin Connector demo is read-only. Registration is not enabled on the demo forums nor on the demo WordPress site. However, you can use this demo to preview some of the features/functionality of the plugin and also how comments look by default. Comments can be styled to your liking via CSS.
In this post, the first thing you will see below is the Debug Mode boxes. Debug mode will help you configure and setup the plugin. Below those boxes, you will see a default listing of comments pulled from the demo vBulletin forum.