Again on the surface it seems unlikely that books would ever need a database for anything, for there is more similarity between books and static HTML websites than between books and dynamic apps with a database underneath. Until we look at workbooks, drawingbooks, sketchbooks and note taking apps.
I suspect that native is going to lead the way here, especially with drawingbooks (paper apps anyone?) that emulate physical paper and a pencil. Given that alternative forms of input are now closer to how we use our hands in the physical world, I have a gut feeling that scroll and pointy buttons will take a backseat soon.