Duh, 2 settings with the 6-core: AI Overclock Tuner -> DOCP, DRAM OC Profile -> DDR3-2000 MHz, another 2 minutes, optional, to set the CAS Timings beyond 'Auto'. I don't deem this as an OC.
Ditto MOBO with 'OC' DDR3 2000 MHz: P67, forth coming X68 or the X58. Meaning there's NO MOBO where you pop-in 2000 MHz and presto you've got correct 2000 MHz, CAS, or in many instances voltage being set optimally.
Now, if the real question is AMD vs Sandy Bridge then yep I'd go the SB + P67 now or wait and SB + X68 in a matter of months. If you're an AMD guy then wait for the Bulldozer.