The TBLC digital download site is an early example of what libraries can become. Hard copy books, CD's, and DVD's aren't going to vanish overnight, but it's already clear that downloading music and movies is a common practice. Downloadable audiobooks are the current stage of evolution that began with books on vinyl records and books on tape. And in many ways, a downloadable eBook is just a long email attachment with a nice cover.
The process is still going on. What we have now will seem primitive and clunky in a few years. So, jump on now! The ride is just beginning.