Is the American middle class radically shrinking?

The rich are getting richer and the poor are getting poorer at a staggering rate. Once upon a time, the United States had the largest and most prosperous middle class in the history of the world, but now that is changing at a blinding pace.

http://finance.yahoo.com/tech-ticker/the-u.s.-middle-class-is-being-wiped-out-here%27s-the-stats-to-prove-it-520657.html