believe it or not, i believe we have one more update of the powerpc powerbook, i think we will see maybe by november(announced at paris expo) either a dual core g4 pbook, or a pbook g5(1.4ghz) available only in the 15" and 17" config, i would personally prefer to see a dual core g4 because they pack some amazing technology, use less power, create less heat and can fit in a 12" pbook, i am guessing more along the lines of an update to combat this recent ibook update, look at the memory of the 12" pbook and 12" ibook, it should be the ibook with 256+256mb dimm, not the pbook. Come on apple.
That is why i think we will see a new pbook by the end of the year, before the intel pbooks come out. dont forget said "we have several new and exciting powerpc products in the pipeline" i dont count this upgrade as new and exciting, though he might.