I have owned a Kindle since it was first introduced; I have never seen the Sony version.
Does the Sony version allow one to purchase newspapers, blogs and magazines wirelessly?
I do, of course, have various books on my Kindle. Yet it is wonderful to wake up Sunday mornings and think about which Sunday newspaper I want. The New York Times? Chicago Tribune? Or one of the United Kingdom newspapers? There is even a Chinese newspaper I enjoy (in English).
Then, with a touch of a button, and a 30 second wait, the newspaper is on my Kindle. During the day I may read a blog (George Will, The Onion, etc), or I may buy a magazine (Reader's Digest, Newsweek, The Economist, etc).
Books are just a small part of the Kindle experience.