That being the case, let me start off with a disclaimer: I have nothing against ebooks. Or rather, nothing except that there's no flipping around in one. I am the sort of reader who constantly turns back and forth through the text, cross-referencing, remembering important quotes, or re-reading sections.
Electronic texts are useful in their own right; I have a Kindle—one of George's old Kindles, actually; thanks, George!—and it's great for getting free classics, finding book club books inexpensively and easily just days before book club meets, fitting more than two books into a purse, and the like. I always miss the flipping around, though.
But the question of the day is the hard-copy printed word, and why we need it, to which I say: We more or less don't. According to Wikipedia, the first known literary texts date to around 2600 B.C., and the world was around for quite some time before that. Which is not to say that books haven't been a necessary part of progress; of course they have. But information is preserved in a lot of ways, and whether that involves printed pages and glued or sewn binding is a matter of practicality, not of morality.
The print book will have its defenders for some time yet, however, on some grounds. For starters, even if all mainstream reading went digital tomorrow, the book as a physical item would be part of history and worth preservation as such. I've got lovely memories of peering into dimly-lit glass boxes and reading Hebraic letters—I couldn't often translate the words—from the Dead Sea Scrolls. Likewise, of trying to chant songs from bright and beautiful hand-illuminated manuscripts from the Middle Ages. It's from this same instinct that I've one shelf dedicated almost entirely to carefully-bound and especially to old books, some of them almost too fragile to read.
As a matter of everyday reading, the difficulty is that I learned to read on print copies and my comfort lies entirely within that zone. It's in the above-discussed flipping around, in questing for a line by memory of what quadrant of the page it fell upon, in what Masha described as "a sensual connection to the words":
I really like the feeling of holding a book. I like the texture of pages - thick, cream-colored journals or barely there Bible pages. I like the scent of books, old and new.... I don’t have an emotional connection to my laptop like I do to my books, I can’t fold down page corners and write in notes in my margins. I think we need books to continue connecting our minds to our senses and to have something meaningful that lasts when technology fails.I think you can dog-ear and make margin notes in some electronic formats, if you're less of a Madam Pince than I am. But while I do have an emotional connection to my pretty pink and gray laptop, which holds the books I've written myself, for reading I prefer to get away from screens and buttons and slick plastic and instant searchability. It's nice to feel plain paper in my hands, to re-read parts and keep fingers in various places, to not have to wait that blink for the page to turn, to simply escape the computer and revert to my childhood understanding of the universe.
But that's just me, after all. It says nothing whatsoever about future generations—or even, necessarily, about my own. Not everyone spent as much of their childhood as possible snuggled away somewhere with words printed in black serif font on white paper. Nor does everyone read in such a non-linear fashion. The Kindle fire burns brightest among those who read books once straight through, and it feeds on books designed to be read that way—crime fiction and category romances being among the popular examples. There's something to Kit Steinkellner's question of whether the genre you're reading changes the medium you read in.
Perhaps children born these days will reminisce in their thirties about cuddling down in a fleece throw and brushing their fingers across their ereaders' touch screens. Perhaps technology will have progressed to the point where they can flip around in their electronic books as easily as we do in print copies. Or perhaps no one will care about flipping around the way I do, not having learned to read that way.
If they ditch our print books, though, they'll have to find new ways of decorating their homes. As for me and my house, we preserve the family library. If our heirs decide they don't want the burden of it sitting around their living room someday, I ask only that they treat history with respect.