This movie is a lot of fun for a lot of reasons, and a lot better (in my estimation) than the reviews. It also has three powerful witches, all of whom are beautiful (at least initially--and heck, even in "Wicked Witch of the West" form, Mila Kunis is hardly ugly. There is also a magic battle between Glenda and Evandora, among other things.
Since the witches have actual magical powers, and the "wizard" is but a mortal man, once has to wonder why Glenda doesn't simply rule by her own powers. That thought comes up with the original work too.