Print is particularly important for learning and "deep" reading. I find my IQ is at least a few points higher when reading in print rather than on screen. eInk devices are kind of good, but made awkward by the 0.5 sec screen refresh delay... There is something to be said about the versatility of hypertext, but I think we lose something in concentration, attention span, etc. because of the links.
What does bug me about ereaders is the software. I have 50 or so books on my Kindle and instead of just quickly grabbing a book off of my bookshelf and reading it until I want to grab another I have to scroll through and find the book- where the screen refresh DOES become noticeably annoying. Not to mention I own a ton of books on my Kindle that I've forgotten about simply due to the fact that they're hidden on page 10 of the library list.