Some concepts are just too good to give up. The codex is one of these.
When scrolls were little more than the ‘score’ behind the recitation or performance of a story, one never used the written record without ‘singing’ it. The codex and it’s close cousin, the index, made written language a new form of memory. It changed forever our use of memory, our approach to retrieval, and the notion of information distribution (publication) as a means of dissemination as well as retention.
Whether developers recognize it or not, users still subconsciously desire some kind of visual feedback when flipping through multiple pages of content. Some of these visual cues are comically exaggerated (iBooks), some are more subdued (Instapaper’s “Fast Pagination” action) and others fit somewhere in between (Flipboard). But each presents a challenge to developers attempting to blend the tactility of real-world pages with the digitally native tablet aesthetic.