IBM Unveils the Power 6:

If some analysts were predicting difficulties for IBM when Apple decided to move to Intel CPU, today's announcement proves they were wrong (deeply). IBM unveiled its new server PowerPC processor, aka Power6, clocked at 4.7GHz, a record for a commercially available CPU. When looking at the specification of "the fastest microprocessor ever built", it illustrates IBM's state of the art in designing CPU: 65nm engraving, 4.7GHz, 790 million transistors, 8MB cache. In addition, the Power6 Bandwidth scores a new record to 300GB/s...
At the time of the Power4-derived PPC970, IBM was facing major issue with power consumption and heat release, ultimately pushing Apple to use Intel processors (mostly for powering notebook models). It seems that IBM made major improvements as the Power6 clocked at 4.7GHz is reported to consume as much as a Power5 clocked at 2.2GHz...
Of course, we will not find Power6 in our Mac anytime soon, as it is designed to find its way in servers, and compete with HP, Sun or Dell solutions running on Intel Itanium or Sun Sparc CPU.