Philipp Lenssen discovers that Google Groups Adds Rating, Author Profiles. If you navigate your way to Google Groups and view any thread or post. You will notice that there is a link to "view profile" of that poster, on the right of the profile link would be the rating and at the bottom of the post is a way for you to rate the post.
Philipp notes that this adds a great "social layer" to the Usenet posts. The user profile link not only gives you information about the poster, but also shows you an historical archive of all the user's posts.