I don't know, maybe if prices for agricultural commodities skyrocket, SC farmers will be in good shape?
I doubt it'll be golf courses or beaches. It probably won't be cars, banking, real estate, or home building. We haven't really succeeded in attracting R&D or technology; you could hardly find a tech job in SC before the recession.
If I was a betting man, I'd say it'll be tied to providing services for retiring boomers. The Rubber Factory plan would be to increase access/affordability for community colleges (esp. nursing), and keep state taxes attractive for retirees.
Or we could sit around and wait for a smart group of people to invent something.