I think the issue basically comes down to preference: there are advantages and disadvantages, some of which I talked about from my point of view here: http://jseliger.com/2010/09/29/the-last-word-on-this-version... .

I still mostly read physical books -- in part because I'm in grad school for English Lit, and the edition problems with eBooks makes them hard to cite and harder still to cite authoritatively.

But a doctor I know observed that he and his wife switched to Kindles because now they don't have to take 10 lbs of books with them, per person, when they travel. I definitely identify with that.