I485 is approved today. It was a long waiting. I filed the I485 in Dec 2003, and did fingerprinting in Dec 2004.
When the application past the processing date in July, I called the USCIS and contacted a congressman and a senator, both of whom were very helpful. I got an email from the congressman's office two weeks ago, saying my case was waiting for security clearance for a while and they were going to contact FBI on this issue. My feeling is that probably helped a lot, though I am not very sure.
I want encourage people to talk to your congressmen or senators if you face difficulties with USCIS or FBI, or other government agencies. They may be able to help you out sometimes.
Good luck to all of us,