I could see it eventually where you get a free digital copy of the book when you buy the full price new paperback. It really doesn't make sense to be spending a lot extra for the digital text restricted e-license which they already have to print the book. Its not permanent enough and too restricted to justify anything but a marginal extra cost. I think the benefit will be people reading more books and the industry will get more profit through that factor.
In the case where you just want to read a book once and never reference it again you could just find a book club where you like to read the same books and share a library and split the cost up to six ways. A family could do the same thing, just like a real home library.