Before I took my kids, I read the reviews on this site. I have to say they left me ambiguous about going - but the kids insisted. Boy am I glad I did. I think they did a great job - and James Franco is perfect as the wizard. He is a cad - but with a conscience and Franco plays it well.
The movie had the difficulty of having its audience know the ending - but being curious as to how they got there. I think there was a lot of symbolism. This is one of those movies that will get credit later.
Only negative was the slow pace in the beginning - but it all comes together in the end.