My son's birthday was this weekend, and this (and Juno) was what he wanted to see. There was some really cool CGI with sabertooth tigers, mammoths, and some Jurassic Park looking huge killer ostriches. The scenery too, with the pyramids being built was decent. I really wasn't expecting Apocolypto (which I thought was fantastic), but at times this movie felt like it was trying to be Apocolypto. The acting wasn't great, and you'd have to get past the "hmmm...this ancient tribe from 12000 years ago is speaking.....English," but while thought it was overall pretty good, I'd be hard-pressed to recommend anyone else dropping $8+ on it.
I didn't see it, but this movie is getting trashed on Rotten Tomatoes. My kids don't even care about seeing it. I thought the first Cars was easily the weakest of Pixar's films, so I'm not too surprised to hear the sequel wasn't that good.