This article in the New York Times describes the test, some of the evidence concerning the association, and some of the issues surrounding its costs/benefits.
My favorite line:
Dr. Foster suggested another way to determine if a child will be good at sprint and power sports. “Just line them up with their classmates for a race and see which ones are the fastest,” he said.Dan MacArthur has done some of the primary work on this locus and its association with athletic performance. I'm surprised his name didn't show up in the article. Actually, I just noticed that he has also written a blog post about this article.
He discusses the tests' limitations and mentions that this test has been commercially offered in several countries for some time and is available through the personal genomics companies in the US.
There are indeed many limitations to this test. Given what goes into making a great athlete, I see no use for it whatsoever, except for giving some solace to a person wondering why, after years of training, he/she didn't become the great athlete he/she hoped to become. Given the predictive power of this test, I think that the costs (mostly psychological) of doing this test to see what you would be good at greatly outweigh the benefits.