I've never been bored at DL and my son is younger, so I'm not sure what would interest yours.
Let's see....
Ask him if he can find all the hidden golden 50's
Send him over to DCA to ride the e-ticket rides (Tower of Terror, CA Screamin, Maliboomer....see how many times he can ride each)
Send him to ESPN Zone in Downtown Disney, he can watch some sports or play in the arcade
If he's into video games, he might find something to entertain him in Innoventions in Tommorowland - they've got a virtual reality game/ride and multiple video games