After trying to phone the National Visa Center for almost 3 months, I finally got through yesterday afternoon. The operator said my petition was approved and forwarded to Manila that morning :-)
The prevailing wisdom had been that the NVC averages about 12 weeks to process the petition after you send back all the paperwork that they require. That was a pretty accurate estimate because ours took 12 weeks and 3 days from the time they received our package of completed forms.
So far, just about 8 months from the time I first mailed the application to the CSC in May.
Ray