My biggest concern is that the addition of millions and millions of Kindle users to a library system that already has long wait times will just make things worse.
I guess my ability to request an epub title and get it within a few months will shortly be ending. Nice that I can now read library books on Kindle as well as my other readers. Sad now that the wait time will be in terms of years, especially if there is no ability to return the book early. What a major error. I go out of my way to return books early. If everything is 21 days it will just make things worse. 4 copies; 21 day wait per; 70 requests = 1 year wait. I would often see this and yet, I would get the book in 3-4 months.
Not any more, with 6 Million plus Kindle users, short waits are over.