Automation will replace more than just the simple and routine. IMO software like Watson may start to replace jobs that require people to do low-level, intensive research. Paralegals, junior lawyers, and clerks who help prep for a case may be replaced by a system that can scour and analyze tons of materials far faster than any human could. What about transportation? Automated cars are in their infancy, but how can we not imagine we could have a world full of automated (non-Skynet) taxis, buses, subways, container ships, or oil tankers?
Some may say those people displaced can re-educate themselves to find jobs requiring more skills, but after they graduate will we be sure they will be there?!
IMO this is ultimately a race to the bottom. It's still a ways out in the future, but I imagine there will be a world consisting of a few managers who control the computers and robots, and the masses who were replaced by them. We may need a new social contract.