Makes a huge amount of sense for Amazon, but honestly I can only see this as a bad thing for Goodreads. Amazon has huge issues with reviews of the fulfilling company getting blended in with reviews of the actual product, and there's another layer added with media - quality of the content, completely separate from the build (pages falling out, horrible OCR, etc).

Goodreads has reviews of content quality. Amazon will muddy that immensely with reviews of every other part of a sale if they do any integration into Amazon (unless they plan an overhaul of their reviewing architecture - I'd love it, but I doubt it).