I think, like others, that this isn't a great movie for those under the age of 10, with Santa being in jail. I believe that most kids are told that Santa's not real around the age of 7, and that you shouldn't watch this movie right after.
We watched it this past weekend, and we loved it, though, and the youngest in the family is 12. We thought that the older brother was a bit of a shmuck in the beginning, but he gets better. We didn't like the fact that Santa didn't need his hat after all; it kind of took the whole point of the movie away.
I think its a great movie for teens that may struggle to believe in themselves.
Kurt Russel really did a great job as a sassy Santa Claus, and perhaps some kids will enjoy a good movie without a cliche Santa Claus, one that they've seen time and time again. This Santa was sarcastic and funny, yet they managed to tie some things in, such as checking the list twice, which ended up being funny with the elf.
For a kids movie, I would give it a 3/10, but for a group of teens, I would give it an 8/10!