Very nice, very funny, easy to watch and enjoyable movie (pre-ordered the DVD the same night).
Prior to its cinema release, I watched the previous two "incarnations" with some friends to be up to speed story-wise - which proved to be unnecessary as the story does not refer to any previous encounters (at least, not that I have noticed). Well, one should have some acquaintance of the characters of Ice Age 2, but that's all.
Overall, a very funny continuation! Question is: will there be an Ice Age 4? ;)