Actually, I felt the same

難以置信! -- I had the same feeling when first reading the email from USCIS, which says "this case has been approved. On May 5, 2005, an approval notice was mailed...". Then I logged in my account set on the USCIS website for checking case processing status, all the I-485 cases of mine and my family's were just updated and the same information as provided in the email was found there. I even double checked the case numbers appeared in the updated information/email, it is for sure those are exactly I-485 case numbers of mine and my family's. Anyways, I will get the hard copies of the notices in few days, which will tell me the final results.

Good luck to all!