Sarah,
I am flattered!
First make sure you hit all four parks. Focus on thrill rides, if that is what he likes. But make sure you do some of the more traditional kid rides. It is always fun to be 8 again, and this is the place to do just that.
Plan at least one night in the Epcot World Showcase. There are so many dining choices, he can find something right up his alley. Or maybe he is a beer fan? He could try some pretty exotic choices.
Arrange something out of the ordinary. There are surfing lessons at Typhoon Lagoon, which few people can say they have done. There is scuba diving in the Living Seas. There are lots of other outdoor activities too.
Finally, enjoy some of the nightlife. I mentioned the Epcot World Showcase, but there are some great lounges at Downtown Disney (Raglan Road, House of Blues), and the BoardWalk (Jellyrolls).
Let's take this to the next level. Write me back with a few things he likes to do back home, and maybe I can come up with a very specific suggestion. Let me know about hobbies, sports, favorite foods, etc.
Have a magical vacation!