It's not a high priority feature, but it would look better if you could have some kind of popup/lightbox displaying the comment policy message or maybe a slider that hides the text and expands it only when you click on the "Comment rules"-link.
If you have read the rules once you probably don't want to read it every time you write a comment.

I tried to use the {tab} tag, which is the "Tabs & Slides (in content items)" Plugin (
http://extensions.joomla.org/extensions/style-a-design/tabs-a-slides/1046) inside the comment policy message, but that didn't work.