Maccentral quotes Dave Russell, Apple's director of consumer-education mobile products, on the state of the iBook. Of note, he hints that the G4 is not likely to appear in the iBook in the next iteration:
"As for what we're looking for in terms of an education-consumer portable, the G3 chip offers plenty of punch," Russell said. "The performance of the iBook is quite fine right now. The G3 chip doesn't draw much power, doesn't generate much heat and runs Mac OS X just fine. We think the G3 has a lot of life left in it. I don't know that the latest iBooks will be the last ones with G3 chips."