For every one that dislikes touch screens, I am guessing there are probably at least five who prefer them, or don't care one way or the other.
Of course, some touch screens are better than others, and some touch software is better than others. Nobody prefers 'bad'.
But by the same token, some keyboards are better than others, and Kindle's keyboard is one of the most limited ones I've ever used (ok: worse is text entry on a numeric keypad). On the whole, I don't think I would miss it, especially if doing so allowed for a larger screen or smaller form factor, and locale-specific keyboard layouts with a virtual keyboard that let me enter accented characters, if not entirely different scripts.
As far as touch screen with e-ink, I don't see very many people unhappy with their devices on the Sony forums here. I haven't tried out their latest models myself, but by all accounts they work quite well. Of course, both Kindle and Sony customers are self-selecting populations, and cognitive dissonance being what it is in terms of human nature, we always make the "right choice."
I am much more concerned that there
be a reasonably efficient way to navigate and enter text and annotations than I am about the specific method (physical vs. virtual). I can type about as fast (or slow, depending on reference point) on my Kindle's keyboard as I can on my iPod Touch's virtual keyboard, and my skills on each continue to improve. But as human interfaces, both could be significantly better than they are right now (not only in terms of general function but in addressing special requirements). So I hope the human interface engineers are not complacent about this.
So, yes, Amazon has to think about all this and be sensitive to everyone's varied requirements and preferences if they want to remain successful. I would guess that means the continued availability of a Kindle with a physical keyboard, but it does not preclude existence of a Kindle without one in the future.