If the iPad and its successor devices free these people to focus on what they do best, it will dramatically change people's perceptions of computing from something to fear to something to engage enthusiastically with. I find it hard to believe that the loss of background processing isn't a price worth paying to have a computer that isn't frightening anymore.
In my mind, Fraser Speirs nails it. At the end of the day all the people outside of tech that I've talked to claim to want an iPad. Why? Pure simplicity.