OP- have you decided which way you're going on this yet?
Here's my .02...if you want to go back to the area you currently live after law school, definitely rent it out! If you can cover the mortgage, taxes, insurance, and regular upkeep through the rental income, it'd be a win for you. I don't know what the rental market is like in your area, but being on the beach, you might
just be able to charge enough to cover it all. And, if you could only cover the mortgage, maybe your wife's income would be enough to take care of the rest? It would be tough to lose a house you love (and on the beach, no less!) just because you're going to be away for three years. And, if you have family in the area, they could screen potential renters for you. Or, you could hire a management company like Matthies suggested. Good luck, that's a tough one