It’s been suggested here that C.S. Lewis would be upset that Narnia is being made into a live-action movie. I respectfully disagree.
When Lewis wrote the quoted letter, he had no concept of what would be possible using computer-generated imagery. Granted, I haven’t seen the film yet, but I don’t think it goes against the intent of Lewis’ letter, even if it does fly in the face of the “letter of the letter” if you will.
(To give proper credit, I actually found this post on TallSkinnyKiwi’s blog