Grafton seems to be seeing an either/or proposition where a both/and exists. There is no reason why the digital library or digital books need to replace real books or real libraries. Nor will they. The good thing is that, when you find something you want to quote from a book, you will be able to find a digital version, which you can then copy and paste into a text you are writing - no need to type it all out by yourself. And that's just one example.