Since he majored in "pre-NBA," perhaps he can go to grad school now and get a masters in "post-NBA," with a focus on unrealized potential.
Would think that he has the option to make plenty of money overseas if he wants to go that route. Also, he is probably a few injuries away from getting another NBA look. If that does not pan out, he could always turn to MMA.
His biggest issue has always been his attitude and work ethic (or lack thereof). What makes you think he'll find the motivation to work out and prepare to get punched in the face when he couldn't even get himself into shape for camp?