It usually takes a few months from the time a chipset first rolls off the assembly line, to when computers with those chips are ready to sell. Apple's not going to have computers ready tomorrow based on chips that it doesn't even have on hand yet. Given there's only a month and a half left in the year, and we're in the holiday shopping season, I doubt Apple will want to shake things up and annoy potential buyers until after Christmas, even if it COULD release a Penryn based MBP in time.
If you take a moment to look at the Intel roadmap, you sould see the Penryn Processors flagged as potential porcessors for updated macbook pro's won't even officially be out till January. The recently released Penryn's (i.e., those on November 12th) are not the notebook processors but the quadcore desktop processors. That is why Apple is expected to release macbook pro updates in January not before christmas.