This is one of the reasons DH is now being assimil.... er... thinking of getting a Kindle, too. On his last business trip, half his baggage was books and they're heavy. He still ran out of books before the trip was over. I loaned him mine to read a book on to see if he likes it. Thankfully he's a very fast reader. The ergonomics didn't suit him quite as well as they suit me but he was surprised how little he noticed it not being a paper book after awhile.
I used to always bring a roller and a backpack and not check bags if I could help it. Having a reader makes that a lot easier. With the liquid rules I now have to check a bag so I can pack toiletries. Now I'm thinking it would be best to only bring one carry on and just check a big bag. I don't want to fight for bin space.