two points:
1) NBA drafts on potential. A not-ready-yet guy is often what they're looking for, just like buying an under-performing stock before the price skyrockets.
2) The kind of money thrown at these kids is hard for anybody to pass up.
justin might return for his senior year if:
1) he and his family are very comfortable financially.
2) the fun he's having at unc greatly exceeds the stresses and hassles of a big time athlete
(note: chances of him returning are higher if he has a girlfriend on campus. anybody heard anything?)