Via what interface would people use the agents? Voice to text on a smartphone? That's clunky and slow and only works in quiet areas where you can talk freely. And mouse and keyboard is really not that hard. If anything was going to kill PCs, smartphones & tablets would have done it, but everyone I know still has at least a laptop. Overall I think getting people to trade in the freedom of having their own personalized devices for a remote agent is a much harder sell then you're making it out to be.