According to Xinhua report, there were about 3,000 real estate development companies in Beijing last year.  Due to the government's effort to cool off China's white hot real estate market, 473 real estate developers disappeared last year. 

In addition, the housing development authority in Beijing estimates that another 2,000 of them might also disappear in the next 5 years.

Beijing is not the exception.  This is happening in many cities.  In Wuhan, for example, more than 200 real estate development companies disappeared in 2011.  This compares with 1375 registered developers now.