there have been rumors going around about certain biostar motherboards being able to unlock the 4th core of the x3 chips. I almost bought a system today to tinker around with, but backed out once I found out how much new tires cost.
Certain Asrock M/B's will do it too but you don't buy a chip because some early buyers got a bonus. The 720 is a Black Edition and OC'ing to 3.0 would just be a matter of changing the x14 to an x15. No muss, no fuss and there is more available cache for however many cores are in use.