I wouldnt take much notice of this information, myself.
If moto can get enough yields of faster G4s then they will produce them. Especially seeing as these new G4s seem a hell of alot better than the older ones.And seeing as these new chips seem a much more refined G4, i am expecting them to scale clock speed better.
But that is possibly not what is holding apple back. If moto are going to produce chips above 1Ghz then apple needs DDR mobos, if there arent DDR mobos then performance is significantly hampered on a 1Ghz+ chip. So it could be that the lack of DDR mobos will be what prevent apple from releasing a new G4.
The new powermacs are cheaper than they were before, so possibly a new mobo is possible. Apple knows that the Powermac line needs DDR, they wont piss about waiting for the right moment while the PC opposition get further ahead.
As for the powerbooks, well they dont need DDR. So apollo based mobile chips arent stifled by that. Again powerbooks are falling behind the competition, seeing as this is a market where apple kicks ass, i dont think they will wait around until they fall behind.
From now till the G5 is introduced, apple wont do as much strategical releasing of products as they have been doing over the past few years. They are behind the PC competition. They need to be near the competition to get the apple name out there before the G5 is released, this will give the G5 a chance.
Apple has shown this by releasing the imac a little prematurely, sure its good value, but its a little expensive for a consumer machine.
Right now Apple doesnt care, they just want to catch up.