If I am correct the Wolfsdales came out after the Q6600 and those clock up very easily. The New QX's seem to go clock crazy too (but those really crush the wallet).
I don't know anything about Intel or AMD's future CPU plans I usually just look at them as they release.
But I say for whats currently on the market, the 9850 Black Edition once the SB750 hits the market. I know some people have had issues hitting even 3.0 Ghz, but that just seems crazy to me. I was able to hit that on stock voltages. And my board is actually messed up, the new one arrives today and this one is going back, so hopefully I can get some better results.
I know that a lot of people are hitting 3.5Ghz on water and one guy hit 3.7Ghz, but thats all with the current SB600, with better voltage control on the SB750 those clocks will go up. The big question remains is, what will stable clocks be on air? Not everyone has the wallet to Watercool.