Staying at Duke another year v. going into a locked-out NBA:
Games: If he stays in college he's guaranteed to be part of 35 or so actual games in front of thousands of fans. In the 1998 lockout, the NBA season was only 50 games. The NBPA seems better prepared this time around, which could lead to an even longer lockout.
Money: If he stays in college, he doesn't have to worry about living expenses, but his family won't see any immediate financial benefit from his success (unless he transfers to Auburn to play QB). On the other hand, he'll have living expenses and no salary if there's a lockout, but some shoe company will make sure he doesn't go hungry. Assuming he "only" gets a 7-figure endorsement deal, going pro is going to be a better financial decision in the short term, both for Kyrie and his family. In the long term, more time in college should make him better prepared for a life outside of basketball, but barring injury, he's talented enough to make more than enough money playing to be set for life.
Basketball Development: Personally, I believe this is the least clear-cut thing that could factor into his decision. By staying in college, he'll have another year of learning under one of the best coaches in all sports. He'll also be guaranteed to play actual games. However, he won't be able to spend all his time playing basketball, because he'll have to balance basketball with academics as well as the NCAA rules limiting practice time. If he goes pro, he might not be getting as good of coaching, but he'll have more time to focus on basketball and he'll be practicing against better competition. I know that if there's a lockout there may not be (m)any team practices, but he'll still be able to play in summer leagues and spend more time working out with other NBA players. Granted Blake Griffin's situation was different because there was no lockout, but it's hard to argue that he would have been better if had he spent a year rehabbing at OU instead of in the NBA.
There are certainly a number of other factors that will weigh into his decision and ultimately, he should do what's best for him and we should respect his decision. For selfish reasons, I'd like him to stay at Duke for as long as possible, but can't fault him for leaving if that's what he chooses.