Took my 3 year old to see this in the summer, and couldn't really pay attention to the movie. :) But, she's watched it about a zillion times since I got the DVD for her, and I have to say that I really enjoy the movie the more I watch it.
Just saw this one. I'd give it 7/10 right now. I saw it with my toddler, though, and the sound in the theater wasn't that great. I know I will like it more the next time I see it.
I am also considering taking my 3 year old daughter to see this (her first trip to the theater!). She loves Toy Story 1 and 2 and Finding Nemo so I'm hoping this one will be about the same tonally as those three.