If you are a Harry Potter fan, it is defintely worth seeing. But you need more than an hour or two to do it. You need to do all three rides at least once, go in all the stores, look in all the windows, check out Moaning Myrtle in the restrooms, find the Gringotts ATM, sit in the owlry, eat at the Three Broomsticks, or at least go in and see how similar it is to the movies- and the Hogshead too! And don't forget to watch the students from Hogwarts frog choir perform a concert, and the students from Durmstrang and Beaubotons (did I spell that correctly?) do their show also. Did I forget to mention the wand picking the wizard at Ollivander's? Lots to see and do! Can't wait to go back. Last time we were there was in early June 2010 when it was only open to the resort guests and people who had HP packages for a few hours each morning. Definitely want to see it at night!
And don't forget to try the pumpkin juice and butter beer (frozen is our favorite). Take lots of pictures.... Truely awsome!!!