Rise of the Guardians went a bit heavy on the saccharine for my tastes.
It's a fun show, and if you've got kids who are in the "I believe in Santa" demographic, this film will play quite well. Anybody who loves books like "The Polar Express" (but not the movie, which was an abomination of uncanny valley-ism) will enjoy Rise of the Guardians, and frankly, there's a lot of fun stuff in here for everybody else.
Sadly, the best part of the trailers -- the subversion of stereotypes for Santa and the Easter Bunny -- only carried the first half of the film for me.
There are interesting discussions to be had with regard to the mythos, and whether it suborns the belief systems currently anchoring Christmas and Easter, or instead stands as a metaphor, giving believers new modes in which to express their beliefs.
I enjoyed myself, but I've had lots more fun at other shows this year. Rise of the Guardians comes in at #22 for me this year as of this writing. Very Lorax-ish. If you haven't seen Wreck-It Ralph yet, I strongly recommend that film over this one for your holiday trip to the cinema.