This would seriously undermine the College game IMO. I don't see how, either the NCAA or the NFL would want to see this happen. I completely understand the financial ramification of this but I don't see how this could be a good thing for the actual sport.
If he does it, it's only a matter of time before you see Sophomore's doing the same thing. If you move the age limit back to try and bring a happy medium, then you will simply see players doing this at an earlier age.
I don't know what the answer is here. I think you have to play and I think injury is part of the game. If you kill the game, you kill the golden goose and that is not good for anybody.