I know what you mean about rereading old books! I certainly have loads that I look at now and think, okay, we're done with you, what next? :D Can't bring myself to throw out many of them, though.
It's funny, Kindles still seem like such a new thing, yet even they're at an age where you can have "old Kindles". I certainly look down on the newer ones with the artificial light and things. I'm not a fan of them trying to make them more like smartphones, either. The whole point is to have a device that's solely about reading books, you know? Keep it that way.