I-485 approved on Dec 31, 2007
details:
05/21/2004, filed 140/485 NIW at TSC
04/18/2005, 140 approved,
2006, wrote a letter to my Senator;
08/03/2007 3rd finger prints;
09/05/07, wrote a letter to first lady;
10/01/07, wrote a letter for FBI;
10/31/07, card ordered for all the applicants.
Called USCIS several times in August, September, and Oct.
You might want push them to let it happen to you.
Good luck