Nope, no ratings whatsoever.
I never saw a real need for it. Although after reading many threads about it (mostly here in the MB forums) I can see it's use, but not for me. I like my music. That's why I have the CDs and tracks that I have. Yes, of course there are tracks that aren't as great as others, and that's what the "skip to next track" button is for. And if -really- dislike a ripped track, I have a DELETE button.