The price of existing Quads with B3 stepping are starting to fall slightly. This may be because retailers are clearing shelf space for the latest variant. The "Gee Zero" has a TDP of 95W, 10W less than the B3. I guess this may translate as slightly higher overclocking potential with your existing heatsink or perhaps just lower temps. Anybody buying a Q6600 after the July 22 price drop has filtered through can check to see if they have bought old or new stock by looking on the packaging or processor itself for the sSpec Number:
B3 Stepping = sSpec Number SL9UM
G0 Stepping = sSpec Number SLARC
If you haven't been able to contain your excitement and prematurely inserted your Quad into those 775 holes, you can fire her up and check the CPUID. Joy or despair will manifest itself thus:
B3 Stepping = CPUID 06F7
G0 Stepping = CPUID 06FB
I appreciate not eveybody needs or wants a Quad but I hope this info will prove useful to other "bang4buck" shoppers out there.