At a recent AILA Conference, Michael Ayetes (USCIS Associate Director, Operations) announced, that during the months of July - August 2007, USCIS had received approximately 800,000 employment based adjustment applications (I-485s): 40,000 concurrently filed with I-140 petitions, 320,000 stand alone applications, and 400,000 dependent applications.
Of the 140,000 annual employment-based immigrant visas available, second and third preference categories are allocated 57.2%. If most of the employment based cases filed in July-August 2007 were second and third preferences, it could take approximately ten years of allocation to complete all these cases.
Although USCIS has posted on its website that I-485 cases received on or before August 9, 2007 have been entered into the system, a number of attorneys have not yet received receipt notices for cases filed at the end of June and July 2007. Moreover, some cases initially filed in Nebraska and transferred to Texas have now been forwarded to the Vermont or California Service Centers for faster processing of receipts.
USCIS is making every effort to process EAD applications within 90 days of receipt. The processing of Advance Parole applications may be delayed due to the number of cases filed.
A Biometrics notice will be issued even if a visa number is not available at the time.
source: http://www.lewslaw.com/US_Immigration_Updates.htm#10022007a