I think this is such an important feature that it rather is a bug than a feature suggestion.
Everyone wants to rate their music from 1-5 or 1-10 and not only have a favourites collection.

You really have to prioritize such a feature. Bring in Erland to the team and give him salary and he can implement his rating system as a native feature.

As it is now, everyone on the forums tries to add a rating plugin and it is quite a hazzle for some people.