The people
primarily interested in either or both of the battery life or the epaper screen.
I agree on cost. I also think that eInk Corp is screwed. Let me explain - Vizplex screens are expensive, and production has been limited. However, ASUS very clearly mentioned a £250 price point for a 9" SiPix screen reader. This is both significantly cheaper than the iPad (as the KDX is not), and not much more expensive than today's 6" epaper readers.
Unless they can pull something out their hat, as cheaper or more capeable alternate technologies start to come to the market this year - removing the supply bottleneck, the market share of Vizplex
is going to plummet. Given 3-4 years, then yes - I think we'll see very little difference between "internet appliance" and "ereader", but right now the iPad and the Kindle remain very different machines for different audiences.
And...that's why I've started to use "epaper" rather than "eink"