While I love my kindle, I realize there are several social signals that are lost in its use. We used to be able to make judgements about someone if they were reading a book with dragons or wizards on the front (I'm not judging, that was me a lot in high school), or how intellectual they were by how thick or boring-sounding their book was.
On a Kindle all books look the same. Same cover, same thickness, you can't really make an observation about someone, other than they have money to buy a kindle... and they knew what a Kindle was.
We'll just need to evolve our ways of judging people.