They'll most likely reduce the human population of the planet, which globally would be good, but not so good on a personal level
http://articles.mercola.com/sites/articles/archive/2099/12/31/has-any-company-ever-harmed-the-planet-more-than-this.aspx
snip
As you may know, chronic inflammation is at the root of many increasingly common diseases, such as diabetes and heart disease. Food allergies are also skyrocketing, as is infertility, which could also be a potential side effect of GM foods, based on results from animal studies. Monsanto insists that GM foods are no different from conventionally grown varieties, but the research does NOT support this claim. Here is just a sampling of the unsavory findings associated with GM foods:
GM pea protein caused lung damage in mice
Offspring of rats fed GM soy showed a five-fold increase in mortality, lower birth weights, and the inability to reproduce
GM potatoes may cause cancer in rats.
Male mice fed GM soy had damaged young sperm cells
Bacteria in your gut can take up DNA from GM food
The embryo offspring of GM soy-fed mice had altered DNA functioning
GM foods lead to significant organ disruptions in rats and mice, specifically the kidney, liver, heart and spleen
Several US farmers reported sterility or fertility problems among pigs and cows fed on GM corn varieties
Bt corn caused a wide variety of immune responses in mice, commonly associated with diseases such as arthritis, Lou Gehrig's disease, osteoporosis, and inflammatory bowel disease
Investigators in India have documented fertility problems, abortions, premature births, and other serious health issues, including deaths, among buffaloes fed GM cottonseed product
end snip