I have to agree with JSWolf, ZodWallop and Cinisajoy. While ereader's still don't look like a traditional book I'd rather lug around 8oz of electronics than 1-2 lbs of paper, ink and glue. Plus at a couple inches thick a book like War and Peace is hard to hold open in paper. Not so with an ebook edition.
Maybe one day there will be ereaders that have pages like a traditional paper book but until that day comes the present ereaders aren't doing that badly as a media either.