I have a first gen Kindle and I love it despite hating on Amazon so much these days. The e-ink display is just the best. I also use their Kindle for PC on both my laptop and netbook--my netbook in particular has that annoying "can't see a damn thing in sunlight" issue, but other than that, it's like have a second and third e-reader. Plus i have all my purchased books downloaded in multiple copies (amazon does allow you infinite downland of books you already purchased, as far as i can tell. They haven't stop me--some of the stuff I've downloaded over 5 times).
E-readers have certain significant problem that will likely not be able to be addressed effectively in my lifetime, at least, so there will still be a market for books, like anything to do with visuals, graphics, symbolic languages--anything that's just easier to print out than convert to an e-reader, many reference materials and textbooks are still far easily to use in book form than in e-reader form.
For academia, research, sciences and such areas, printed books will remain very important for some time yet, although online resources are competing to some degree. But for leisure reading, e-readers will likely continue to in in use and popularity. Not only are they convenient, user-friendly and likely to improve tech-wise in the coming years, they are sensible for avid readers looking to spend less, be eco-friendly and conserve living space.