Well, according to Suze Orman just about everyone should wait until 70 years of age. I read the same AARP article as Sean and was a little concerned also by her advice. Social Security planning is not a one-size fits all solution. Waiting until 70 may make for a worthwhile mass media sound bite (and, logically, one should wait if they can afford to), but many folks can't or shouldn't wait. Why shouldn't they wait? Consider the following:

Maybe longevity does not run in your family;
Maybe you have a chronic illness/condition;
Maybe an individual can't work or can't find work commensurate with their education/experience level;
Retirees who have too much debt; and/or
Folks who are willing to accept a lower standard of living so they don't have to go to work anymore.