"Yes, e-readers are amazing, and yes, they will probably become a more dominant reading platform over time, but consider this about a book: It has a terrific, high-resolution display. It is pretty durable; you could get it a little wet and all would not be lost. It has tremendous battery life. It is often inexpensive enough that, if you misplaced it, you would not be too upset. You can even borrow them free at sites called libraries."
I would add that books are a lot more fun experientially to buy in person and you never have to worry about formats or platforms when sharing. Other advantages come to mind?