I think you've got yourself a great idea and a great name to match.
When I think about all of the sites that have been around for some time that allow you to "rate your boss" or "rate your professor" or "rate XXXXX" it makes me think that libel is not quite as big an issue as some people would think.
How many great (popular/profitable) sites would have never been created if their owners would have legally picked them apart piece by piece before they created them?
"What every man needs, regardless of his job or the kind of work he is doing, is a vision of what his place is and may be. He needs an objective and a purpose. He needs a feeling and a belief that he has some worthwhile thing to do. What this is no one can tell him. It must be his own creation. Its success will be measured by the nature of his vision, what he has done to equip himself, and how well he has performed along the line of its development."
-Joseph Morrell Dodge