Ok, so I don't think all that many of you belong to this movies target audience - however I'd like to share my two cents. I've never been a big fan of the "Ice Age" movies. I enjoyed Scrats antics in the first one but not enough to actually watch "The Meltdown". That being said, I'm a very (!) big fan of Pixar's work, with "Ratatouille" ranking amongst my favorite movies of 2007. (with "Pan's Labyrinth" coming out on top, if anyone cares). So where does "Horton" fit in? Right along with BlueSky's "Ice Age" I'm afraid.
Kids might dig the elephant's antics, I was mostly bored. There's the usual pop culture references including an extended animé (!) sequence which absolutely doesn't fit in with the rest of the film, some instantly forgettable one-liners (e.g. "I love the smell of bananas in the morning") and not much in the way of stunning visuals. The morale comes hard and heavy, being driven home with the force of several sledgehammers.
There are some redeeming qualities like a predictable but still hilarious sequence on a bridge, but they are too few and far between to actually merit a visit to your local multiplex. Unimaginative, technically average and short on laughs. Bearable, but instantly forgettable.