From CNN (emphasis is mine):

With home sales plunging to their lowest level in 15 years, economists warn that a double-dip in housing prices is just around the corner, threatening to further slow the overall recovery.

Existing home sales sank 27.2% in July, twice as much as analysts expected, to a seasonally adjusted annual rate of 3.83 million units. Much of that drop is attributed to the end of the $8,000 homebuyer tax credit.