I'm with Iniewski on this, quite honestly. There is always that potential for, "You have really crappy genes. Merry Christmas!"
If there's something credible one can do to remedy a problem, that's one thing. If there isn't, I don't know how others feel about it, but I'd sooner remain blissfully ignorant!
I think, unless you were adopted, you probably already have a pretty good idea about your genes - at least as far as potential health concerns.
Getting DNA tested isn't just about uncovering potential medical issues. Many people are using it for genealogical research and to find out more about their ancestry and/or to connect with genetic cousins. A DNA testing company that focuses more on this aspect is Family Tree DNA:
I looked into this and though finding out more about my DNA sounds interesting, the survey stuff seemed kind of creepy. Once they have your DNA, they want you to answer all kinds of surveys so researchers can find trends with genes and personality type. It sound like it would lead to pseudo science gene analysis, like employers using handwriting analysis to weed out job candidates. It's all too GATTACA for me. I don't trust anything these Google guys do.
I have several family members who have tested at Family Tree DNA and they have never been asked to fill out any surveys. Perhaps 32andMe is different, but in any case I suspect fears of all this giving rise to a Gattaca-like society are overblown. (But it did make for a great movie.)