Last night on NOVA scienceNOW there was a segment on the personal DNA tests currently being marketed to consumers (you can watch the segment on the website, unfortunately no ability to embed video on other sites). The host, Neil deGrasse Tyson, had his DNA tested by Navigenics and learned his "probability" as compared to the rest of the population for getting certain diseases; even deciding to learn the genotype associate with his APOE4 gene, the so-called Alzheimer's gene (something James Watson decided not to do when his genome was sequenced). As all the scientists who do not work for one of these personal genomics companies said when interviewed, while these tests may provide some information about a person's genome, we really don't know what they are telling us about the person's health, how the SNPs detected affect phenotype, how to use them to guide lifestyle, treatment, diet, etc.
Later in the program there was also an interesting segment on geneticist and rocker, Pardis Sabeti, who pioneered a statistical approach to determine if mutations in a population were random or enriched due to natural selection.
Speaking of Neil deGrasse Tyson, check out the tour of the Hayden Planetarium he gives to Stephen Colbert so Stephen can become an astrophysicist if the Colbert Report doesn't pan out.