I think it's an interesting idea, but it also reminds me of Foursquare Tips. The underlying ability to pipe tweets through sentiment analysis and then to other services, even to businesses own customer service centers, is key to this product.

I feel it it too abstract at at this stage

No need to tell me you are going to tell me the problem. Just tell me the problem. Give me an example of what kind of review you are talking about - okay. CF example is okay. How are you going to make money? Leave revieews through twitter. Nice look and feel. Review service. Makes sense -