I think he appeals to ALL age groups...my 7 & 9 year olds love him, as do I (34) and my ex (46) and my mom...as well as my brother and his friends that were 20 & 21. That said, I've seen large groups of teens (cheerleaders, I think) really get into the act, and enjoy his show!!! I think it depends on whether the teens are fun-loving or just "too cool for it"! WDW has a way of sucking the "cool" out of alot of people though!
Give it a try, there is an arcade there too if they want to hang out there as well.