The last edge e-books have over hardcovers, and paperbacks too in this case, is accessibility. If you have an Internet connection on your e-book reader, you can buy books 24 hours a day, from the comfort of wherever you choose, and, you have them virtually instantly. It's not a huge deal to go to the bookstore and pick up something new, but it's an extra step, especially in some cities where parking isn't always easy! And sometimes, that book you want isn't available at the store (though there's no guarantee it's available as an e-book either!) so you have to order it and wait for shipping.

These factors are significant enough for publishers to worry about the future of hardcover bindings. I believe it's inevitable that volumes bound in hardcovers will become the realm of the collector. They're inherently more collectible than paperbacks when considering condition, ability to withstand time, and production runs. Of course, responsible collectors will, after buying a hardcover, never open it to maintain condition. If they actually want to read it, I'd suggest downloading the e-text!