While I agree that the additional cost of the BlackBook prohibited me from getting it (actually I was pretty much sold on the entry level MacBook with larger hard drive... but had they offered it in black at the same price, i would have gotten black) if you have ever really looked at one, the amount of detail into making black is quite impressive.
The plastic inside the USB and other ports is black instead of the white on the regulars. The color of the cloth protecting the optical drive, is black. The screws are black anodized aluminum. The plastic screening behind covering the speakers in the back, is black. So having to get all these customized parts must have been expensive... probably not $100 expensive, but more expensive. Add to that they probably had quite a bit of market research that showed that more black ipods were sold than white ones, and the decision to charge more was no doubt a no brainer.
You know, if they had charged more money on top of that, but included
Black power brick
Black USB extender
Black FireWire Extender
Black MiniDVI accessories (maybe not included them, but offered them)
Then I would be happier about it. But that they still didn't do all that... and what is really surprising is that no one does! Why on earth not?