Edmund's portrayal was spot on, and Peter's was very close. I was a bit unhappy with Susan's portrayal, and I'll need to re-read TLtW&tW again to see if they were just setting up for future events at the cost of her character in this book. One of Andy's elementary school friends who was best man at our wedding (and whose father performed the ceremony) is a lighting person for Rhythm and Hues, which rendered the show (or at least a large part of it; I'm a bit fuzzy on that), and he said the plan was for four of the books to be made into movies, if I remember correctly. He didn't know which three other than this one were to be made, but I'm guessing The Last Battle will be one of them.
As expected, there were some departures from the books. Most of them I didn't mind; I may be anal about adaptations, but I also understand that things need to be changed for timing, to explain things for people who may not have read the books, and due to the inability for some things to be transferred to screen properly. A few of the changes were strokes of genius which were so in the spirit that I could have seen Dr. Lewis suggesting them had he still been alive. There were only one or two I strongly disliked, and those not so much because they departed from the books. As noted before I'm ok with making changes where they're needed, but in those cases there was no need for them to do so.
I will absolutely watch the movie again if given a hint of a chance. Overall it was an excellent piece of work, and even though I had quite a few nitpicks apart from the complaints listed above, the overall whole is definitely worth it.
This is a no-spoiler post, so please don't post any in the comments. Do let me know if you might want to discuss further and I'll start a new thread with appropriate spoiler protection.
PS: Sign me up to go to Narnia if I get dresses like Lucy and Susan's.