I love the Kindle for 'story' books - novels or biographies, and don't think I'll go back to print books. I know what other posters mean, though - I do miss browsing in bookshops and coming home with a bag of books to read, all shiny and new, clean and soooo tactile. Oh and that smell! And I agree that I was probably much more selective in the old days, choosing my books carefully and rarely buying something I ultimately discarded. With the Kindle, however, I buy at the drop of a hat and have bought some real rubbish, which then gets abandoned 2 or 3 chapters in. But I have also found some absolute gems, that I possibly wouldn't have found in a bookshop, chiefly because of the 'Kindle Daily Deal' which brings quite a variety of books to one's attention. And given that these selections are cheaper than the average magazine, I don't mind risking them.
Reference books, however, must be in print form!