I went to see Up. You ought to do the same. Not only is it primo Pixar work (except for the short in front of it, which I felt was weak), it manages to articulate its theme in a way that other films of the sort never did.
Seriously, what I got out of The Wizard Of Oz was, "Look, there's no point in daydreaming, because satisfaction is available to you right here in the goddamn dustbowl. Oh, and Uncle Jed's allergic to silver paint." Not so Up; this movie says, "Life is an adventure to be savored, so don't overlook the details while you dream your dreams."
Plus: talking dogs.
Pixar, man...I have no interest in seeing the car movie, and that damn fish movie annoyed the crap out of me. But everything else has blown my damn socks off. Even Ratatouille, about which I was indifferent at best, ended up pleasing and surprising me. To say nothing of Wall-E and Toy Story 2...
So. Up. It's Cosgrove-tastic. Go see it, go.