E-books after the iPad

Kevin Rose, the founder of Digg, considering the future of e-books, shares "some random ideas." It's not hard to imagine the implications that some of the features he fancies could have on education, higher education in particular. For instance, consider the prospect of an instructor leaving notes in certain passages of a text. Or a rich multimedia reference function (definitions, animation, video)in text - how might that change the textbooks for biology, chemistry, physics?