World Cup fever may be over in South Africa, but the search for shale gas is just getting under way.

Last November, I noted that Chesapeake Energy (NYSE: CHK) and Statoil (NYSE: STO) had paired up with local energy champ Sasol (NYSE: SSL) to stake some South African turf. Today, Sasol announced that its technical cooperation permit has been granted.

There are a few notable things about this permit. For one, it took around eight months to process. That may sounds like a snail's pace, but Sasol expected this to take closer to 12 months. Perhaps we can read this quicker-than-expected turnaround time as a sign that South Africa's Petroleum Agency is making efforts to speed development along.

The second thing that caught my eye was the size of the permit area: roughly 88,000 square kilometers in the Karoo Basin (a major fossil site that spans nearly two-thirds of the entire country). That translates to about 21.7 million acres, and exceeds the size of South Carolina (ranked 40th by area among U.S. states).

If the shale rock in this vast area is indeed found to contain the special sauce necessary to produce commercial volumes of natural gas, Sasol is hardly overstating the case for this being a "game changer" for South Africa. The heavily coal-dependent country (coal powered 85% of its electricity generation in 2007) has been plagued by power outages for years, cramping the style of miners such as Gold Fields (NYSE: GFI). Inroads by shale gas in the power-generation mix would be welcome for both supply diversity and environmental reasons.

Before you get too excited, though, there are a few more things to bear in mind. First, Falcon Oil and Gas and Royal Dutch Shell (NYSE: RDS-A) have already reportedly scooped the most desirable acreage in the basin. Second, this is only an early stage exploratory permit, and no drilling is approved. Lastly, even if a huge natural gas play is uncovered over the next few years, there will be major infrastructural, equipment, and manpower hurdles to contend with, from gas pipelines to high-powered rigs and skilled rig hands.

In short, I wouldn't own any of these stocks for the potential upside from this South Africa shale play. But there's almost certainly nothing priced into the shares for this potential, either. Consider it a free option on a low-probability, high-impact outcome.