[miketardis]

I loved it. Saw it twice (though not in 3D, which gives my wife a headache)
It amazes me that Pixar can do a film so littered with references or "homages" to other films without ever becoming derivative.
The short PARTLY CLOUDY was really cute, too. I also have to say that I love the charming musical scores to both films (by Michael Giacchino).
It might be worth checking to see if your local theater has really early morning shows. The theater down the road from me started screening UP at 9 AM, and the first 3D showing was at 9:30 AM. I'm sure the former was pretty much deserted, and the 9:30 showing yesterday had maybe 30 people total in the theater.
The film worked for me, especially the extended montage near the beginning that managed to get me teary-eyed. (Of the four movies that have ever managed to get a tear rolling down my cheek, three of them have been animated, and two have been by Pixar.)
The B-plot that drives most of the action did feel as if it had been spliced in from a completely different movie...more like something out of a '60s or '70s Disney cartoon. On one hand, I think it might've been a bit more satisfying if there weren't a mustache-twirling villain, but on the other, that plot introduces a really wonderful, endearing character, so it all evens out. (I'm trying to be vague to sidestep around spoilers. The fact that so much of this comes out of left field in the movie is part of the fun.) It otherwise plays to Pixar's strengths: jaw-droppingly gorgeous visuals, rich and layered characterization, wonderful performances, such confidence in its playful sense of humor that it doesn't really go for easy laughs or obnoxious dance numbers set to flash-in-the-pan pop music...

[Hailstorm]

The wife and I took it in for our 38th anniversary at Disney World last weekend, we did see it in 3D, well worth the extra money.