Of course, kind of Ipad will overtake notebook and smart phone also will encourage this. But a smart phone is not a PC, so we will ever need of a PC near. However, the PC will seem at an Ipad, even if it's not designated by Apple and because we need concurrency.
The fact is Apple create the tendency. But look at a firm like HP, which has understood too late the curb of his old model. I don't remember who have told that, but she said HP has finally made a good thing, they have invested in smart phone technology. The bad thing is that they believed it was necessary for them to buy Palm.
In the future, the screen will be replace by just a laser, or your telephone will be like a creased paper that you get out of your pocket and unfold.