Oh give me a break. Publishers will put themselves out of business. In the music realm we recently saw bands like Nine Inch Nails and Radiohead release their own albums for FREE (donations and paid collectors versions available) and make as much or more money than they would have going through a music publisher.
If they lower author royalties, how long will it be before Grisham just says 'screw it' and releases an ebook only release in conjunction with Amazon. The publishers do what exactly with ebooks? Their very existence is questionable in the next 20 years. Lowering author royalties isn't going to help them.