My brain is still a little fried from having been at Butt-Numb-A-Thon, but the 45 minutes of Pixar’s Up that I saw is still rattling around in my damaged brain pan.

While there may have been more clips shown at BNAT than is needed at a film festival, the first 45 minutes of Up is footage I wouldn’t trade in at all. What we saw was sometimes fully rendered and finished, sometimes flat and undone and often just sketches and storyboards with a temp music track and voices dubbed over, but it was completely engaging and often beautiful, visually and emotionally.

What you know about the movie is that it’s the story of an old man who floats his house away with a ridiculous number of helium balloons and that a Cub Scout-type comes along with him for the ride. But that’s just the opening of the film, and there’s more going on than just that. Giant crazy birds, talking dogs and primordial South American jungles soon come into the picture. I have a feeling that the film continues to expand even beyond what we saw, as Pete Docter said that Christopher Plummer plays a major character who had barely been seen (and who is likely the antagonist).

The reason a 45 minute presentation of mostly still or barely animated images can work so well is that Pixar places so much importance on the story and the characters. The animation is gravy. Based on what I saw, Pixar has again created a couple of great characters that manage to be funny and completely human at the same time. That humor/humanity split is also present in the story; there’s a montage showing the lives and love of Carl, the crotchety old man played by Ed Asner, and his wife Ellie that’s more touching (in rough form!) than the entirety of The Curious Case of Benjamin Button, but is still filled with humor.

If the rest of the film continues building in quality from the excellent 45 minutes I saw,Up is guaranteed to be one of the best films of next year. My biggest hesitation is one that seems restricted to just me, namely that this film could be another Wall*E: a movie with great promise and a great build up that doesn’t quite stick the landing. I know that Up will have adventure elements in the second half, and I almost wish it didn’t.

But all of that is the future. For now Up stands as the most promising Pixar movie in years, and certainly one of the most exciting films of 2009. I can’t wait to see the rest.