The Tuscaloosa Marine Shale in Mississippi and Louisiana could become the next U.S. drilling hot spot, according to this article. The need for advanced technology and the cost of drilling are impediments, though companies have been renewing leases. "If they're holding on to the leases for another five years, they must think there's something there," said Richard Metcalf of the Louisiana Mid-Continent Oil and Gas Association. "I think it's still early in the development of the field. But with each well, they're learning more and more."