I thought it was interesting in this article that they used the new Chronicles
of Narnia movies as their main example of quality story telling and sticking to
the original author's story. I personally thought they did a horrible job at it.
The whole part in the movie about the evil green mist is nowhere in the book. I
thought it was silly and all the time spent on that could have been better spent
on following more accurately what actually happened in the book. Of course,
that's just my opinion.