I disagree. The E6850 (65nm) and E8400 (45nm) have identical clock speeds (3.0ghz), multipliers (9x), and fsb speeds (1333mhz). Of the two evenly matched processors the 45nm E8400 is by far the better overclocker. The only reason the 65nm quad cores are better overclockers is they have higher multipliers than the 45nm quad cores currently available.
I havent tried clocking my Q9450 just yet, but im considering going for 1600FSB to put me on par with a Q9770.
And i agree with you puddle jumper, people have taken a 9650 past 4.1Ghz, which people would struggle to do with a QX6850 which is the same spec with 65nm process. The only disadv for 45nm is less posible vcore voltage, but 1.4v Max is stil safe. My Q9450 takes in more voltage than my PD (1.28 vs 1.20), and is still happy.
if those 45nm can take the voltage the 65nm can it would be insane. 1.4V for me seems like nothing. I used to pump way more than that daily. Then again it is only an $80 chip so I really don't care.