* The touch UI will not completely replace the existing input methods you describe, and the tablet will not completely replace the laptop.
* The tablet may be enough for the majority of mobile users.
* The touch interface may suffice for the majority of tablet users.

The choice of computing device and interface should be left to the individual user. Some users who only need a tablet with touch, may choose a laptop with trackpoint or mouse. That's still their choice! It's not up to anybody else to tell them otherwise.