I love Narnia, but I don't think a Narnia land would really fit in Disneyland. A ride could go in Fantasyland or Critter Country if absolutely necessary. But live-action, 3-D talking animals aren't really the same as the animated talking animals of Critter Country. And live-action tales of daring don't quite mesh with the animated films of Fantasyland, either. And as noted repeatedly, where would they find the room?
(Of course, I don't really like Pooh being used so heavily by Disney either. Although, the animation style of Pooh isn't too far off of Song of the South, so it works better aesthetically than Narnia would IMO. Pixar items probably don't belong in DL as well, but I like their recent films so much more than the recent Disney films, so it's hard for me to rail against using them.)
As much as I'd love to see Narnia in a park I can actually visit without too much trouble, I don't think the British story would fit at all in DCA. I DO think a Narnia land in Animal Kingdom could work, though; it seems like they've gone towards talking dinosaurs on occasion, so why not talking animals? If done well, I'd love to see it, but I think DL is full enough of (mostly) Disney characters, they don't need to kidnap them from other sources.
(I would kind of like to see a Narnia show in Fantasyland Theater, though that might be partly because they need SOMETHING there to keep people off the crowded walkways!)
If a Narnia ride WERE put in, I wonder what it would entail? Just another fairly low-budget dark ride, or something immersive? I like the Dawn Treader idea (even though it was my least favorite of the books, really). Or maybe the Dawn Treader could sail around the Rivers of America, and the river scenes could be replaced by Narnian ones?