Search by sentiment? — Cool idea!

Have you ever wished that you could search all the user feedbacks for a certain product that you want to buy?  Sure you can search for product reviews but nowadays most of the feedbacks by the real users are done via blogs, Twitter, Facebook, etc…  So imagine consolidating all those feedbacks for a product that you want to buy then basing your decision on those feedbacks.  I think that would definitely help a consumer make a smart decision.  Well who knows, maybe the next evolution of Google would include search by sentiment.