I don't usually link to blog posts with lists, but Nathan Bransford has posted ten common e-book myths, and reasons why they are simply not true. It's a smart post, and it answers most of the major concerns about e-books.
8. The reading world will be divided between those who can afford an e-reader and those who can't.
While I think this is a legitimate concern, over the long term: 1) I think the price of e-readers and multifunctional tablets are going to decline to the point of affordability for just about everyone, 2) print will still exist, 3) libraries will still exist, 4) e-books themselves will be cheaper than their print counterparts.