According to the Register the upcoming Intel Prescott processor will never exceed the 'magical limit' of 100W power dissipation. Intel says that the entire line of Prescotts will consume between 90W and 100W. A few months ago some sites rumoured that the Prescott would consume much more than the current Pentium 4 line, somewhere between 100W and 110W.
At Intel Developer Forum, company CTO Pat Gelsinger said that 100W was OK for a desktop computer. While he wasn't referring to Prescott directly, his words did seem to confirm the suggestion than Prescott would run rather hotter than its predecessors.
And now it's official: Prescott will run at 90-100W. The statement confirms PC Watch's original claim.