Saw this on our (Aust') version of 60 Minutes the other night.
Article and Interview here.
Genetic research has come considerably far in the past few decades, having now reached the point where they can pinpoint certain genes that cause particular features within our own body, including the development of disease and ill-health. Essentially, you can send your DNA off for a test (for a hefty price o_O) and they can determine that likelihood of you developing a certain disease in your lifetime, anything from Alzheimers, to cancer and heart disease.
I guess this begs the biggest question, would you want to know? Keep in mind that it's all done in likelihood, and that you may not actually get any of them, or you may develop a few of them.
I personally would do the test on the basis that it's a not a window into the future per se, but gives you a largely general idea about what could be in store for you. Whether the results come back optimistic or cynical, I may find some comfort in knowing that I could prevent it, or at the very least build up some defences today so I'm less susceptible in the future.