We'll know the solution is near at hand when there's a satisfying way to represent a book like "House of Leaves" (colored words, intentionally blank/sideways/mirrored pages, backwards text, and other typographic mischief) or "Gödel Escher Bach" (diagrams, puzzles embedded in formatting, messages riffing self-referentially on the medium in which they're represented). This is apparently a long way off, given that after all these years, the Kindle hasn't even evolved to the point where it can render a page without what is often sparse and uncomely full justification (to the best of my knowledge).