First they promised it, then they delayed it, and now they cancelled it. Intel has failed to come up with a 4,000 MHz version (4.0GHz) of its Pentium 4 CPU. The fastest available is 3.8HGz.
The original master plan had been to eventually ship 10GHz CPUs. The Register notes that it took Intel two years to increase the Pentium's speed by a mere 20% -- something that used to take just a 1/4 of a year.
The spin is that the company will instead try to increase speed through means other than GHz -- faster bus speed (faster communication between the CPU and other parts of the computer) and cache size (larger amount of memory inside the CPU itself).