It seems that Christopher Tolkien shares his father's view that faithfully transferring the story to film is simply impossible. JRR Tolkien only sold the movie rights because he needed the money.
Books and Film are two different media in which to tell a story and I am surprised that some people have expectations that a film will be just like the book. They are just setting themselves up for disappointment in my opinion. I think it is possible to venture too far from the spirit of a book but for the most part a film will be a different interpretation of a story.