[Richey79]

I agree with Clancy.

Worldwide computer ownership is estimated to be something less than 5% (just as an indication of technological-penetration. The ebooks that really proliferate may well be those that don't need to be connected to a computer). The only way ebooks will overtake pbooks in the majority of the globe - with their durability and ability to work without being charged - is through the one-laptop-per-child project, or solid state libraries that are plugged straight into a television.

Then you have the mass of people in the wealthy parts of the globe who will either prefer pbooks, or use them alongside ebooks for the foreseeable future.

There'll have to be much more powerful carrots and sticks before people in general start buying more ebooks than pbooks.

'Take over from' needs to be defined. That's going to represent a fairly arbitrarily-chosen point, unless ebooks get to a point where they are causing printing presses and pbook publishers to shut down.