Watch it happen.
Tablets cost considerably less than desktop computers. There is nothing preventing you from being able to plug a second monitor and a mouse into a tablet and use it exactly the same way that you use a laptop and a desktop today.
At the moment, they're significantly more expensive and less compatible. They're also, by virtue of design, far easier to steal / lose and we've had quite enough (UK) stories about laptops being left on trains by mistake or stolen from homes and critical data being leaked as a consequence. Also, I can't see many people wanting a 10" desktop monitor or a 17", let alone 22", tablet.
I don't dispute it could happen, but I'd be surprised.
The home market may primarily shift to tablets; I'm not convinced by that and I think there's still a problem with the use case for content creators on tablets which includes an awful lot of school children. But the market I absolutely can't see abandoning PCs as we see them now and moving to handheld touchscreens is the office market and that's far from insignificant.