My I-485 file is at National Record Center?

Hi, I have a question: my I-485 is pending, for 3 years. I went to the immigration interview on 6-10-08. as of today, there is no result. So I called the service phone3 and they told me that my file is in National Record Center and they had to request my file. After they review my file, they will let me know my I-485 status...so what the hell is that? Could any expert in this forum clarify my situation for me? Many thanks.