I wish there was no need for publishers. Unfortunately, publishing is not isomorphic with printing/distribution. Editorial services and book design are pretty much vital to the process of turning a manuscript into something people are willing to pay money to read, and marketing is necessary if you want to convince folks to read your book, rather than Dan Brown's.

We may see a realignment of the way publishing services are applied to books (e.g.: author hires editor and PR folks to work for them, or literary agents hire editors and turn into virtual publishers -- they've got the accounting infrastructure to handle royalty payments), but we already have authors selling directly, and there's a reason most readers usually avoid self-published books.