AnandTech has taken a look at Intel's upcoming 65nm processors. They also checked out the overclocking potential and were able to clock their single-core 3.6GHz Cedar Mill as high as 4.50GHz (stable). The dual-core 3.4GHz Presler processor managed to reach 4.25GHz.
They also checked out the power consumption:
Under full load, the Cedar Mill system at 3.6GHz drew 176W while the Prescott system at 3.60GHz pulled 213W, an average of 21% more power than Cedar Mill. The move to 65nm definitely helps, but AMD still has the low power advantage. While we didn't have an identical AMD system on hand to compare exact numbers, Intel's 90nm Pentium 600 series chips have generally consumed as much as 50% more power than AMD's 90nm offerings.
Read on over here.