As an overseas missionary living in Peru, I find an e-reader of the utmost necessity since it's much more difficult to obtain books in my native tongue here, therefore the internet and online bookstores, such as Amazon, help me keep up on world news and and obtaining the latest books I seek to read. Barnes and Noble for example, had already adapted to this trend and release a device to rival the Kindle, called the Nook, which has for the first time just barely beat Amazon at their game.
Barnes and Noble seemed to rightly understand that the way to grow, was to offer what customers want in the way they are now wanting it. We have seen this pattern with digital media, it's only a matter of time before it is an even more pronounced change and tipping point with books, and maybe even books only being offered in digital format due to the costs of printing not being found as profitable anymore. The liquidation of Borders is just a sign of the times, a reference point of a bygone era that may be jumping into the past faster than some of us may think.
Who knows, but you better hold on to your books. They might be a collector's item sooner than later.