No G5 Powerbooks
Despite rumours about G5 powerbooks being on the way (partly fuelled by the discovery of some HTML code on the Apple store containing the string 'Powerbook G5') it appears that it's not to be.
There were some performance increases unveiled and a new scrolling touchpad, but all models still use the G4 processor (which is good if, like me, you just bought a G4).
The reason that Apple have given is that the G5 is just too power hungry and hot for a laptop. That would make it bigger, heavier and noisier than current Powerbooks, not Apple's style.