FWIW, this NY Times article from May claims the USDA isn't too impressed:
The market could be vast. In North America, up to 40 percent of crop-loss insurance claims are due to heavy or moderate drought, according to some estimates. Worldwide, corn-growing regions lose about 15 percent of their annual crop to drought, and losses run much higher in severe conditions.
However, Monsanto's corn is unlikely to perform well enough to tap this potential, USDA found.
While the agency's draft environmental assessment of the modified corn found the crop unlikely to pose a plant pest risk, prompting USDA to seek deregulation, the agency also noted that many corn varieties on the market match Monsanto's strain in their water use.
"The reduced yield [trait] does not exceed the natural variation observed in regionally-adapted varieties of conventional corn," the report says, adding that "Equally comparable varieties produced through conventional breeding techniques are readily available in irrigated corn production regions."
Given the slight improvements made by the corn, the agency does not project that approving the variety would cause an increase in corn cultivation. Last year, U.S. farmers planted some 86.4 million acres of corn, 86 percent of which was genetically engineered to grant resistance to insects and weedkillers.
Any significant advance in drought-tolerance will I think have a dramatic impact on world food supplies, but if the USDA quotation is correct here then it doesn't sound like they are there yet.