Are 400 Equal to 180 million?

According to Forbes Magazine, in 2009, the 400 richest individuals in America had a combined net worth of $1.27 trillion dollars. That is more money than the bottom 60% of all American households! To put that in raw numbers, 400 Americans have more wealth than 180 million Americans combined! Is it just me, or is there something horribly wrong with this statistic??
 

To further elaborate on the growing wealth disparity that is occurring in this country, here is an excerpt from Edward Wolff, a Professor of Economics at New York University.  He is the top academic expert on economic inequality in the U.S.

"A somewhat rough update, based on the change in housing and stock prices, shows a marked deterioration in middle-class wealth. According to my estimates, while mean wealth (in 2007 dollars) fell by 17.3 percent between 2007 and 2009 to $443,600, median wealth plunged by an astounding 36.1 percent to $65,400 (about the same level as in 1992!) ... Trends in inequality [from 2007 to mid-2009] ... show a fairly steep rise in wealth inequality ... The share of the top 1 percent advanced from 34.6 to 37.1 percent, that of the top 5 percent from 61.8 to 65 percent, and that of the top quintile from 85 to 87.7 percent, while that of the second quintile fell from 10.9 to 10 percent, that of the middle quintile from 4 to 3.1 percent, and that of the bottom two quintiles from 0.2 to -0.8 percent."

Note: a "quintile" is 20% of U.S. households, so the the middle and bottom two quintiles include 60% of U.S. households.