We took our 4 yr old to see Shrek. It is just as good as the others. There were some points during the movie that my little one got bored. They put alot in there to keep the parents entertained, but the kids loose interest. All in all, its a good movie, we will probably buy it when it comes out.
In our area, you can save money by going to matinee(before 4pm), saves about two bucks a ticket. If you want to see it in 3D, it cost about 3 or 4 dollars more per ticket. There are usually coupons in the paper for concessions. One of our theaters offeres $5 large drink and popcorn on Sundays.