The first time (after small-babyhood) that we brought DS, @ age 2, we did all the Sing-a-Long tapes, and got the Magic in a Box promotion, which was really neat. He enjoyed watching it all and singing the songs. He still didn't quite get it, though; he wasn't jumping up and down on the plane in anticipation, and he seemed to be in sort of wherever mode, "one plane ride is as neat as the next, destination doesn't matter."
He really liked the Swan, where we stayed that time; he's fascinated by fountains, and the Swan has plenty. As to the parks, however, he was still just sort of going along for the ride until we got into the MK that first day. Walking back to Dumbo, he looked up and saw a character. "Hey??? Mommy, did you see that? Daddy!" ... And then another one, and another, and then, wonder of wonders, a Dumbo he could actually RIDE! He got up into the air and then stayed there, figuratively speaking, for the next 5 days.
On the next trip, he was excited from Day 1 when we told him, because he knew what was coming. On our next trip later that year, when the plane landed, he followed all of the rules and stayed quiet until the moment we came to a stop at the gate, then yelled at the top of his lungs: Yea! Disney World!!! ... and started jumping up and down. The whole plane erupted in laughter and applause. I'll remember that moment until the day I die.