HotHardware has posted a review on the Pentium 4 2GHz CPU
Regardless, this new P4 is much more compact size and it's package seems far better suited for dissipating heat. This allows for lower core temps, as you will see in the pages to follow.Read more
One note is that Intel plans to offer a 2GHz. Socket 423 version but that is the end of the line for the 423 pin out. Higher forthcoming clock speeds will all be in this new 478 pin device.