Motorola announced a new version of the G4:
"Compatible with the entire PowerPC family of microprocessors dating to 1991, the MPC7410 is the first of Motorola's microprocessors to be manufactured in the HiPerMOS 6 (HiP6) 0.18-micron copper fabrication process. This move to
Motorola's most advanced manufacturing process, and the resulting small die size, are part of the reason the MPC7410 has a typical power dissipation of only 6 watts at 550 MHz, making it ideal for high performance embedded systems. "
Embedded systems... and powerbooks perhaps...