E-Readers Should Scroll Smoothly
I predict that e-book readers of the future will use smooth scrolling instead of page turning.
Page turning requires you to reach the end of a text area, decide you have to perform a UI gesture, perform that gesture, wait for the device to respond, and then find the beginning of the new text. Smooth scrolling uses a continuous interaction style that helps you keep your place on the page, and doesn't require you to move your eyes around as much. It encourages flow.
In fair disclosure, page turning allows the user to feel a sense of accomplishment and completion when turning the page. These advantages, however, are outweighed by the importance of flow for consuming large amounts of text. Consider reading articles on the web with smooth scrolling versus page up/page down, for example. Flow is really important.
The Kindle E-ink readers can't do smooth scrolling because their screens take a long time to update their contents, but normal display readers like Kindle PC, Kindle iPad, and iBook should all default to smooth scrolling.
I think Kindle on the PC and iPad mess this up because of legacy thinking from their earlier Kindle devices. Apple doesn't do this because they're taking skeuomorphism too far. But eventually e-book readers have to come around, and it can't be too soon.