The first desktop-like processor of the 45nm wave, the 3.0GHz Core 2 Extreme QX9650 is set to undergo a few updates as Intel is preparing a new stepping for later this quarter. Planned to be available from March 3rd on, the C1 stepping CPUs will feature new SSPEC and MM numbers and a new CPUID - 0x00010677.
Source
TechConnect Magazine - Intel QX9650 C1 stepping coming in March