I filed 485 mid 2006, still pending. I checked about 100 receipt numbers close to mine and found 24 485 applications, among them 11 were approved, those not approved were all filed on the same day as I did. If this sample is representative, then over 50% of the applications filed around that time are not approved? That's a striking example of the inefficiency of USCIS. Of course there is another possibility, that is, I am in an unfortunate batch of applications.
If you guys have nothing better to do, why don't you do similar thing and share your findings? With enough of information, we might be able to get a better idea of the situation.