I expect that a lot of the reason that this display is (evidently) much cheaper than the screens on, say, the Reader or iLiad, is that it's addressed very differently, I've suggested before
that it's probably a segment-addressed display, rather than a pixel-addressed. I still can't be sure that's what's going on, but from the pix we've seen (especially on Moto's website), it sure looks like that's what it is.
Assuming that is
the case, the cost of the backplane driver would be significantly
lower, and, as orcinus noted, the backplane "electrode matrix" is the expensive part on a pixel addressed display.