As a follow up to my original question: When our P2 Store arrived, it came with a sticker on it that it was fully updated from the factory with the correct firmware for 16 gig cards. Now we'll see how soon the 32 gig cards come out and make this current P2Store an antique.
Just follow the upgrade instructions posted with the firmware at that last link. The instructions are written for the Windows P2 Store Manager, but the Mac version appears to operate identically.
With all the griping going on around here about it not working for Mac...it seems like our friends in Japan have made this work. I never had to boot into windows to make it work. It was all OSX native.
I've searched, and all I could find were posts saying it couldn't be done in OSX, only in Windows. It seems to work in OSX just fine now.