From the website:
Once the user ratings are in place, the comments can be displayed and styled accordingly. Poorly rated comments (too many Dislikes, not enough Likes) can be hidden in a click-to-see link, just like those on Digg. Highly-rated comments (a lot Likes and few Dislikes) can be highlighted. Hotly-debated comments (many Likes and Dislikes) can also be highlighted to draw more attention, to fan more votes and comments.
The thresholds for all three types of comments are configurable. So are the styling. Styling can be done with background color, fonts, etc. on the comment as well as the entire comment box.
This plugin allows using Wordpress as a general CMS in a Web 2.0 fashion. User generated content can be voted by other users. Example website is Caption Wit. Followings are a few example screen shots.
Update: Comment Rating has been discontinued. To access the site, view an archived copy.