They say the market experiences a 10% correction (on average) once per year. And while I haven't officially tracked that stat myself, I would say, from personal experience, that the past 12+ months have been somewhat unusual - in that the market has had an amazing run without a double-digit (%) pullback along the way.
As you might imagine, after 26 years of investment counseling, I have witnessed my share of corrections. And my message, given today's 200+ point Dow drop, is that not once did a correction ever come (on the surface) for the sake of itself.
Never have I seen a headline stating "The Dow's off 200 Today on Great News from Greece". Or, "The Dow's off 2.5% Today on Great Corporate Earnings". Nope, the headlines always read of the crisis du jour, the fear spawned by X...