Previewed at WWDC, launching in the fall.
PowerBook G5... Not Yet...
Most feel that Apple is simply unable to utilize the current G5 in today's PowerBook enclosure:
"It'd be this really thick, heavy notebook, and it would be loud as all get-out," said Kevin Krewell, editor in chief of the Microprocessor Report. "Those would not be design choices that Apple would want to pursue."