My experience with youth in learning environments outside of the formal school classroom is similar to Declan's. The participants are often highly engaged and the learning is more often internalized. I agree that part of the reason may be the built-in fun (one of the boy scout program themes here in the US is "fun with a purpose"), but I think the bigger reason for the participants' engagement may be that they have clearly chosen to participate (the learning is self-directed) and in many cases the experiences happen in an environment that is more forgiving of different learning styles. The learning that takes place is student- (learner-) centric.
Although I do agree that WE modules would be useful in the kinds of youth organizations that Declan mentions, I believe that the open, adaptive WE content currently in development may be the impetus for self-directed student-centric learning to become a reality in many more situations.