Daniel Strauss asks a intriguing question: would Peter Jackson's Lord of the Rings adaptations have been better if J.R.R. Tolkien had been alive to offer advise and consent on the movies? His question assumes, of course, that the movies could have been better under any circumstances, which I'm not sure I think is possible. They certainly could have been different, but I've watched the trilogy, extended and theatrical release, many, many times at this point, and I think it's consistently excellent, and will stand the test of time. And while Tolkien might have contributed some insight, unless there's evidence that he had specific cinematic expertise that Jackson and his entire team lacked, I have a hard time believing that he would have made the movie much better. Adaptations are precisely that: they're not direct translations of an existing work. A director needs to understand a work, but he also needs to be able to look at it with a critical eye, to know what bits of it simply can't translate. Would Tolkien have understood that Tom Bombadil simply didn't fit into the movie? That enhancing women's roles in the movies was important to making them blockbusters? I just don't know.
But for a good discussion from the author end of all of this, do check out Walter Kirn and Susan Orlean on Bloggingheads:
Seems like a pretty great problem to have.