Went with a friend to an advanced screening last night...good movie
I'm a huge John Cusack fan anyway, but this movie has all the right elements of a great family film that even adults can enjoy.
It's funny, sweet, and heartwarming.  Cusack does a hell of a job, and so does the kid.  Of course Joan is in it, and she's on top of her game as the quirky older sister who's switch is just about ready to be flipped.
Go see this movie this weekend, you'll thank me.
http://www.martianchild.com/