What? The stock heatsink worked fine up to like 3.2Ghz on my E6600, but at 3.4Ghz it ran a bit too hot. And thats 1Ghz above the stock speed.
The stock heatsink is perfectly fine.
People don't seem to understand - It is a waste of time getting aftermarket cooling and checking temps if you do not overclock. I'm sure Intel knows what they are doing, and can provide a heatsink that will suffice when not overclocking.
And using a heatsink other than the stock one doesn't void the warrenty. I just read it.