I wouldn't worry. In modern society, every time you open your eyes, there's a very strong chance you'll see some text somewhere, be it an advertisement, a book cover, some text on a screen, your cell phone. There's so much text around that children haven't the slightest chance of not learning how to read unless they have some kind of rare medical condition that prevents them. Of course I'm not talking about poor children in Africa here - I'm sure the iPad version of Alice is not much of a problem for them. And as far as interactivity replacing text is concerned, I wouldn't worry about that either - it's just an evolution of the medium. If interactivity is readily available and easy to implement, there's no reason authors shouldn't embrace it to enhance their works. If they, or their publishers misuse it, I'm certain the readers will set them straight with their wallets.