There should be about 1950 visas left for China EB1.

Based on data from http://www.flynnclark.com/immigrationwritings/2006-7.html As July 2006, China EB1 used 1700 visas in 10 months (Oct 2005 - Jul 2006). China EB1 consumed about 170 visas monthly. Assuming this rate is also applied at current time, then in 5 months (from Oct 2007 - Feb 2008) only
170 x 5 = 850 visas are used by China EB1. Therefore, there should be about 2800 - 850 = 1950 visas left for China EB1 from March 2008 to Sept 2008.