Walt Crawford has published "Books, E and P" in the latest issue of Cites & Insights: Crawford at Large.
Here's an excerpt:
You might think of this discussion as Part 3 of WORDS: THE EBOOK MARKETPLACE. It is another set of notes and comments on material ranging back as far as May 2010 and related to ebooks, but it's really about books and the media in which they appear.
Note another key distinction from previous discussions in this area: E and P, not E versus P. Sure, some of these items make the digital-triumphalist assumption that print books will die out within the next generation (or next five years!) or become irrelevant collectibles, and there may be a few suggesting that ebooks will disappear or become a niche segment (although that seems unlikely). But my sense—not yet tested, since I'm writing this preface before beginning the essay—is that much of the discussion is now more nuanced and plausible, starting with the real-world fact that old media rarely die and the likelihood that there's room in this world for both print books and ebooks, in very large quantities in both cases, for the foreseeable future.