There's no way eBooks will kill books, because they're just not as convenient. It's not really the same thing as with CDs/LPs/MP3/etc ; MP3s keep on growing because they're more convenient than a CD or a LP (to transport them, for instance) - obviously I'm not talking about feeling there -, LaserDisc disappeared because they were ridiculouslyhuge, etc
eBooks are not as convenient as books, at least that's what I feel. That said, there may be a day where the deforestation situation grows so bad that there is no way to print books anymore, or ar least not as many, and not as cheap as nowadays. Just my imagination of course, but who knows.