Just because it's popular, doesn't mean it's been universally well received.
http://www.amazon.com/Gone-Girl-Gill...DateDescending
http://www.bookforum.com/inprint/2003/12173
https://www.goodreads.com/review/sho...w_action=false
I thought it was ok, nothing extraordinary, but I've read elsewhere that people have found it a non-ending, or kind of flat. It's not the worst ending...hard to explain it without ruining it for you. But it's a really good sign that the book author is involved in this rewriting, as opposed to World War Z.