[jharker]

Regarding keyboard vs. touch screen, you have to think of the usage model and target market. The Kindle has wireless internet and book downloading. People are either going to be searching for books, taking short notes, or browsing the web (i.e. searching Wikipedia). For all of these, a keyboard is necessary. With the slow refresh rate of e-ink, a physical keyboard is the only way to go.

And once you have the keyboard, what do you really need a touchscreen for? Scribbling? Taking notes? Maybe, but the slow refresh rate of e-ink makes these things feel clunky at best -- I know, I own an iLiad. I like it, but I almost never use the stylus except to do things that a button could do just as easily. Meanwhile, the trade-off for touchscreen capability is shorter battery life and substantially higher price. In my opinion, it's just not worth it.

Remember that the Kindle 1 had that little LCD selection bar? I thought that was a brilliant design choice. E-ink at the time was so slow that moving an e-ink menu bar felt clunky. The LCD bar was slick and fast, and they could use the e-ink display for the static menu options.

Anyway, the point is that the normal UI design paradigm just doesn't work with e-ink-based e-readers because the refresh rate is too slow. The biggest challenge when designing a reader today is figuring out how to design the UI so that the user won't get frustrated. It's very challenging. All modern design concepts assume a fast refresh rate, so there's no real prior art to work from.