My 10yr old son has never quite caught the Disney magic, but I think he's catching on. We took him when he was 5, 7, 8, 9, and this year, 10. This was the first year that we (me, wife, 10 son, 3 daughter, 2 son) went as a family. My wife and I are HUGE fans and enjoy just the "experience", despite what we do there. Well, I think this was the first time that our 10 y/o figured it out. He watched the little ones react to the characters and it always put a smile on his face. He started really enjoying watching them enjoy Disney. I made sure that him and I would do "big kid" stuff, like E-Ride night and extreme water slides at the water parks. I think that when he first went, he was personally too old to enjoy the characters, so he never had any memories like myself or other kids do when they went at a young age. Maybe as he's growing up, he's starting to appreciate it more from a different perspective.
-Bill