Even so, reviews are more for other readers, than for the author, in my opinion. In a review I don't want to tell the author what he or she should do differently or fix; I want to tell other readers what to expect should they choose to read this book.
If there was a feedback system for the author, I'd use it. For example Smashwords allows you to read the book on line in the browser: It'd be cool if I could just select words there and mark them as typos and at the end of the day the author could see the list of errors and correct them. I just don't see how I could do that in a review. I certainly don't want to read lists of typos in other people's reviews.
Anyway, that's just how I see it. I'm not a writer but I dabble in software development, hence I desperately miss a technical solution to this particular problem.
