Intel Yonah is auto-overclocking
 

If you have a 2GHz 1W average chip, and another that is 2W, they will be in different lots. The 2W part will probably be downbinned to a 1.8GHz model, and it will definitely be a lesser part in the real world.

Rumour has it that the top two speed bins of Yonah will be notably lesser in real world power draw than their lower brethren, leading to 'faster' chips with real world longer battery life. This may explain why Yonah went from a planned 2.5GHz +/- a bin to 2.16GHz, the extra clock was sacrificed on the altar of power efficiency.

http://theinquirer.net/?article=28431

So, how about refund to current P4 customers who chose to lower Cpu Vcore and clock speed in order to lower power consumption?