This is the reason to be interested in such matters, but I fail to see much of interest in this initiative from the strict perspective of textbook quality. (I will admit, however, that I am alien to the current e-textbook market and technologies.)

While fancy galleries, embedded videos and the such are quite nice, I would dare to suppose that they are not exactly novelties in the ebook field. I might be austere, but Apple-style animations seem toyish, distracting and out-of-place. "Dynamically updated data" seems to be only pushable to Dashcode HTML widgets, which might be lacking in flexibility (but I might be wrong). There does not seem to be a framework for mathematical interactions that could aid comprehension, for example, nor one for on-the-fly manipulation of text structure that allows the student to fold blocks/etc., e.g. to focus on a particular paragraph/conceptual element.

Briefly stated: is Apple's "reinvention" merely reduced to a basic authoring tool and a branded store, which can tangentially (but importantly) channel external efforts in the sector?