My birthday was last week and my future parents-in-law got me an e-reader. I quickly became excited about it, even though I'm a fan of the 'ol paper copy books and I hadn't given much thought about owning an e-reader. What I'm particularly excited about is that I can "borrow" a great deal of e-books from my local library and most literary classics are available through Project Gutenberg (helllloooo JS Le Fanu, Alexandre Dumas, and Jane Austen!). It's a bookworm's dream.
There was, and still seems to be, a feeling of anxiety among many that e-readers are the undoing of the book industry. I don't know the figures, but I feel that book lovers will always keep buying paper copies of books. With libraries now lending out copies of e-books, it's yet another way they've maintained their relevance and importance within their community.
Personally, if I read a book I love that I've come across digitally through my e-reader I'm still going to go out and buy a physical copy, because you never forget your first love and your first love is worth bringing home.