This is all anecdotal, but I know a number of people who bought their parents iPads for Christmas. In all those cases, their parents haven't touched their home computer since they got the iPad. The iPad, along with its competitors, are all the computer a good segment of the population needs.
I love Steve Jobs' analogy here. He essentially said that desktop computers will stay around, but they'll be the trucks of a car-dominated industry. My parents (and most consumers) never do heavy work on their computers. What they've always needed--and what these new tablets are finally delivering--is a fast, dependable car that runs a long time between refueling.
