I don't know if this has been done yet, but when I floated a similar idea in a different thread people seemed to like it.
The idea of this site is that it's basically Metacritic, only anybody can sign in and add reviews. It would function based on a nonparametric algorithm. I won't get into the details, but it would mean you wouldn't have to fix everything on a 0-100 scale, because it wouldn't ask averages, it would ask 'Did this publication rate X higher than Y'. For 4 stars out of 5, you wouldn't add '80', you would add '4'.
I would also want to add functionality for user reviews separate from professional critic reviews, so it would have similar functionality to RYM. Except, it would also give the option to make lists based on customized group. You could, for instance, only include users with similar taste to you, or you could only include users who love Bob Dylan.
Feedback? If I produced this website would AMmers use it?