I prefer printed books, but I frequently am reading on the subway, the train, the airport, etc, and so the portability of ebooks is a huge advantage. I'm definitely excited about being able to both pick up a printed copy of a book for leisurely reading at home and have my entire library in my pocket when I have to go fly somewhere.
I infinitely prefer reading a physical book at home, but I love being able to access my Kindle library when I'm out and about.
I want to be able to read every book on my shelf at home while I'm not there, and I'm loving this move on Amazon's part. I just hope it doesn't spell trouble in the long run.