The Sandy Bridge version of MacbookPro's isn't likely to use the quad core version but instead a dual core version with hyper-threading much like the existing lineup offers. According to current Sandy Bridge listings: http://en.wikipedia.org/wiki/Sandy_Bridge_%28microarchitecture%29#Mobile_processors the quad core Sandy Bridge mobile CPU is 45W TDP while the current i7 processor used in MBPs today is only 35W. Due to size constraints and Apple's push to have 8+ hours of battery life they will be incapable of continuing to offering 8 or more battery hours if the switch to Sandy Bridge 45W quad cores is chosen. The current 35W offering of Sandy Bridge is only a dual core with hyper-threading. There's still expected to be some improvement in performance as early benchmarks by Anandtech are showing a 10-30% performance boost per core on the desktop variants. MBP 13" and regular Macbooks should see the switch to Sandy Bridge dual cores due the the integrated IntelHD 200 graphics(which appears to be on par with an ATI 5450) eliminating the need for a discreet Nvidia 320M in lower end models.