Motorola makes the G4 processor. Clock speed is not everything. And Motorola had some problems. There are enough resources on the web about it, though.
To sheepguy42: You only had to disable the onboard graphics and/or sound to work with the AGP/PCI cards. Not really a problem.
However, the PC boards with onboard graphics and sound pose a problem to the iMacs over here in Europe. If you need a 'cheap' computer for word processing, E-Mail and surfing the 'net, you can choose between an Athlon XP 2200+ machine with a 15" LCD for, say 599$ and an iMac for around 1399$ (yes, they're a bit more expensive over here). The eMac is disqualified for more than one reason. Let's just name the CRT monitor that is definitely sub-par. So: Those onboard stuff machines really made the PCs very, very inexpensive. And the fact that you can upgrade them the way you want (processor, graphics card, audio card, video recording cards etc.) make the customer feel more powerful (and they tend to forget that they also pay more if they buy more).
Apple definitely has a problem in the consumer market over here because of that, but it seems that Apple likes to sell us quality, and I think that's okay. It's only strange that the iBook is about the cheapest notebook you can get AT ALL in Switzerland.
I hope it stays that way, but I also hope that Apple does something about the iMac's price over here.