Saw it this morning! Took our kiRAB 7 and 5.
Have to say best childrens film I've seen in ages. We saw Ratatouille and I was amazed at the graphics,but the story was not so good.
However Horton was a great story, great animation (They even threw in some classic Seuss and Manga type animation!) We all enjoyed it, I'd certainly recommend it.
Also saw the trailer for the new Pixar one Wall.E the graphics on that look stunning!