Yes, I was recently given a new Sony Reader (more on the Reader next week), which I then gave to my wife, which, after a week of use, converted her to our new paperless overlords. Enthusiastically. We honestly can't imagine going back to paper books, and in fact, I haven't read a paper book since I got my Kindle. Which was a long time ago.
I asked this question a little over a year ago, and given how much has changed since then with the rise of the Kindle and Sony Reader, I thought it would be interesting to ask it again and see where things stand: