The strain of creeping bentgrass is resistant to herbicides such as Roundup (which, as anyone who has ever used it knows, is incredibly deadly to any form of plant life). The idea is that groundskeepers could spray lawns with very harsh pesticides to kill all weeds, and leave the grass unscathed. Version 1.0, as it were, would be designed for golf courses, but Monsanto and Scott are developing versions for home lawns as well.
However, environmental groups, the U.S. Forest Service and the Bureau of Land Management are quick to point out the downside of "franken-grass," claiming that it could become a "superweed" that could spread uncontrollably and crowd out other plantlife. An article set for publication in the Journal of the National Academy of Sciences points out that the grass has unusually light pollen, allowing it to spread more widely than regular grass pollen.
Monsanto and Scott counter that bentgrass is not known to spread uncontrolled, though no studies have conclusively proved or disproved that such grass can spread unchecked. Biologists note that bentgrass can cross-pollenate with other strains, though Monsanto and Scott say that this particular strain does not.
The next step is more thorough Dept. of Agriculture testing, which could take a year or more. In that time, expect to hear lots of arguments for and against genetically modified grasses.