Also, I think the technology needs to improve before it will have even a chance of supplanting print. I have a Kindle, and sometimes the issues with tzuras hadaf (so to speak) and other essentials are too much to look past. I generally only use it while traveling/commuting – otherwise, I prefer print books when I can get them.
About textbooks – everyone thinks that I buy all my textbooks on Kindle. I bought one, once (under duress, I might add), and it’s HORRIBLE. It was about half the retail price, but exponentially more than the used textbook price – and I can’t even resell it. And that’s the least of it. The pagination and graphics were a MAJOR issue – that it and of itself was a dealbreaker. I suspect it’s better on the iPad/Kindle Fire/Nook/whatever, but then you have all the drawbacks of the LCD…you get the picture.
So no, I don’t think that ebook technology really is in danger of supplanting print. At least not yet. But it really isn’t something to worry about, anyway. 😛