AnandTech dedicated an article to QX9650 overclocking - this CPU has proven to overclock really well.
With much fanfare, Intel released the highly anticipated Core 2 Extreme QX9650 Processor just a few shorts weeks ago, knowing that the high price would be little more than a speed bump for high-performance enthusiasts. More practical-minded users will have to wait until early 2008 before experiencing the mainstream release. Naturally, we wasted no time in bringing you this first-hand look at the QX9650's expansive overclocking potential. Although our experience has not been entirely without problems - we will cover the good and bad later in more detail - we must commend Intel on the development of another great product. Without a doubt, the QX9650 has taken its rightful placed in the winner's circle.
Check it out over here, it's a very interesting read.