Saw the 9:30 PM showing (has the benefit of not having too many young kids; mostly people like me, who grew up with Pixar (incidentally, I remember the first Toy Story when I was, er, eight I think; that's gonna be a massive nostalgia attack next year)).
Absolutely fabulous. Right up there with Pixar's best films (Toy Story 2, The Incredibles, WALL-E). I almost never cry at movies (I can count the number of times on the fingers of one hand), but this movie made me cry twice (both the major stuff related to Carl and Ellie, obviously).
The villain of this one seemed a bit perfunctory; you could really see the core story here working without him, on an emotional level, anyway, though they needed a bit of action and a climax. Though I loved the dogs, and Alpha's Chipmunk-voice.
EDIT - Also, this was my first encounter with the new 3D; there was no 2D showing in my theatre, so I had to go to this. The glasses didn't bug my normal glasses as much as I worried they would, but still: enough with the 3D. It's lame.