I just saw The Lion, the Witch and the Wardrobe and, not having read the books, I thought it was just ok. Everyone who has read the books and seen the movie said it was very faithful to the source material, which is great, but part of the problem with faithfully rendering a book onto film is that good books and good movies are paced very differently. Parts of the movie dragged, but even with the slow pacing the timeline of the plot was hard to follow. I didn't get a sense of days or weeks passing, and yet armies were mustered and battles were fought seemingly overnight. Characters remarked on how large Narnia was, and yet they seemed to traverse the world in mere hours.
The acting was more than sufficient, particularly Tilda Swinton as the White Witch, who was strangely reminiscent of Cate Blanchett's Galadriel from The Lord of the Rings movies. The kids did a great job, and the voice acting for the animals was good. Some of the animation was a bit lackluster, but that may have been by design since the movie was clearly aimed at kids and probably steered away from visual violence on purpose.
On the whole the movie was definitely entertaining, and it gave me an inkling to read the books that I've had on my shelves for years.