When we went in Dec '06 my kids were 7,7 and 5 and they did well, but I thought they would. I personally wouldn't take a 2 or 3 yr old to that show unless they were pretty good about sitting down thru a whole meal. There's not a lot of room for them to meander around if they did get down.
BUT if you did take them and had to leave, maybe you could walk around outside and see the horses, etc while the rest of your party enjoyed the show and dinner.