I've been working on a Style and theme plugin for MC, wich is based on the tags from AMG.
It's a manual process in the beginning to tag the tracks, but in the end I hope there will be enough tags for people to automaticly update much of their library from the user database.
A beta will hopefully be published in a month or two. Been putting it off for a long time now, I know.... To much to do at work.
I'll update the plugin forum as soon as I know more.