I went to see the movie this weekend - it was my 3 year old's first trip to the theater. He had a good time. It was a good experience (sat in the big chair with his own popcorn/soda - got the full experience). We made it through about 2/3 of the movie before he wanted to leave (not because of the movie, but because he is 3 - attention spans are a bitch). He absolutely loved the first one and he seemed to really like this one.
As far as the movie itself goes, it's pretty good for what it is. The action scenes were done really well and the dialog is kinda funny. I'll probably get it on blu-ray when it comes out regardless and I'm sure I'll probably spend at least $100 in merchandising (toys, shirts at Target, etc...). So I guess their plan worked.