Dan, as Carrie pointed out, the primary decision really ends with Walden Media, not with Disney. Disney can pull out of distributing Narnia if they wished to, but Walden Media has not said they will let go of Narnia. However, I think you'll find this article in it's entirity is nothing more than rumour. NarniaWeb's Word On the Street section mentioned this about a day or two after the rumour emerged:
In regards to the link I just gave it refers to a previous article that NarniaWebbers posted (I assume - though I can't say I read that one, otherwise I read it and forgot it), but I'd assume that's where JimHillMedia got their story from.
Anyway, I wouldn't encourage paying too much attention to the rumour unless we get an official word that it's true.