I have been a PDA users for the last 15 years and a Palm user for almost half that time. Unfortunately, as some will tell you, I am kind of evangelical about certain things that have truly changed my life (Palm PDA, Tivo, weekly lawn service, etc). As much as I demonstrate how superior the technology is to datebooks, planners, address books, etc, there is a set of people who prefer the paper. As a matter of fact, one of my old bosses, got a beautiful Palm Vx a few years back from her husband. She spent several days inputting all of her data, and never left her paper. She did end up printing out the address book to stick in her planner (it was cleaner).
The one thing I am sure of, is that there is a set of people (and they are not a trivial group) who will never move to paperless. I work in the Document Imaging industry, so even when they move to paperless it generates more paper. I once had a customer who moved all of their application process to a Document Image system. The process was completely paperless. I later discovered that at the end of the process they were printing every single document out for auditting!!!!
So eBooks, eNews, and all of this stuff will eventually replace paper, but not in the near term. If you would have invested in a paper company when the IBM PC was introduced, you'd be very wealthy.