When I first heard of the idea of making SC PG-13, my first reaction was please yes. You have a lot more freedom with that kind of rating, and to be honest, it pulls in the 16-25 age group a lot easier.
But then the more I think about it, I can't imagine what they'd have to do to make it PG-13. Most of the time, the difference between toeing the line of PG vs. PG-13 has to do with language, not violence. (actually a lot of PG-13 movies will deliberately toss in a couple of words to avoid the PG rating. PG movies do this too, to avoid G ratings. It's complicated.) The last thing I want is the addition of language, and not even necessarily because I don't think there's a place for that in film, but rather because I think there is a place and it's just not used in Narnia.
Quick clarification: ratings are based roughly on language, violence, drug, and sexual content. All language in the books falls under PG levels, even if LotGK's magic fell under the drug category it would still pass PG, and the last category shouldn't be an issue. So that leaves violence as the only possible factor.
And... well, SC doesn't have a lot of violence. In fact, offhand I might even argue that it has the least amount in the series, on screen or otherwise. There are no large-scale battles, the giants throwing rocks is comedic at best (it could be made dramatic, though now I'm thinking Rock Giants from The Hobbit: AUJ and... no), and most everything with the carnivorous giants is done through reference. Such things wouldn't even have to hide to stay PG; they are PG.
As for the tone, yeah it's dark, but dark doesn't preclude PG--after all, movies like The Poltergeist and Jaws were PG (note that I sincerely doubt they would be now, but nonetheless, PG gets away with a lot more than you'd think). "Dark" is kind of hard to assign a rating to, which is why it can toe the line pretty easily. It all depends on how much clout the studio has and how forgiving the Radars are feeling (let's be honest; Toy Story 3 had no business being G, but it got it anyway).
So all that to say... yeah. I don't think SC needs a PG-13 rating at all, or at least it shouldn't aim to be. If by happenstance the PTB decide to assign it to the film, I won't complain necessarily, but I also don't think it's... necessary.
![Tongue :P](./images/smilies/10.gif)