I must have read several thousand books by now. How many of them do I want to actually buy, proudly display on my bookshelf, re-read? Maybe a couple of hundred. For all the rest, there will now be Kindle. The permanent solution to the one-time-read dilemma. It might be a screen and not paper. But as long as I can curl up in bed with it, take it to the loo and the kitchen and the park, it should work.
The other area where it might have a big edge is textbooks. Imagine yearly updates to the Same textbook you have made notes and corrections in. Everybody knows the books you've marked and highlighted in four different colors are priceless, and the pain of going through a woefully unmarked new edition of the same book. Yet, for a lot of textbooks, you have to buy new editions every year! Think of review texts, MCQ collections, high-yield guides!
Now we just have to wait until they downprice it.