I admit I'm different from most people in that I have a tendency to see unemployment as a "free labor" pool. This comes from playing computer games such as Master of Orion 2 or Birth of the Federation where the player's goal is to build their civilization up over the course of many years (turns). A technological advance in say, manufacturing, would result it the same amount of labor producing more or require less labor to produce the same amount thus, freeing up some labor for other important work like scientific research.
Something similar happened when humanity started getting good at agriculture: more efficient food production techniques allowed other people to spend their time living in towns and pursuing professions like blacksmiths, tailors, merchants, doctors, philosophers, soldiers and even lawyers. Despite the resulting massive increase in population, pollution and angry people, we, as a species, are in a better position because of it. (My definition of better position means "more likely to successfully fend off the coming alien invasion." That's another way I'm different from most people but I'll save it for another commentary.) The main difference between the games described earlier and history is that in the former, a single being was carefully planning and directing things the use of labor resources for the best use and overall good of the civilization. In the latter, everyone was (1) independently seeking his or her own self-interests with public welfare coming as a by-produce, as described by Adam Smith's Wealth of Nations [1].
So will automation result in widespread unemployment? Short answer is yes; long answer is no. Any increase in worker-efficiency means fewer people need to be used to do the same amount of work. In the western world, that translates to unemployment but that's not really the fault of the technology that enables this efficiency -- it's just the way the free-market capitalist system behaves. Fewer people will be needed to do the same tasks that were automated and from the individual-worker point of view this is highly negative. It forces them to increase the level of their education and it takes them more time to reach the same amount of wealth and status as the previous generation. If they cannot or will not do this, they will have no choice but to seek employment (2) doing something else. If no state-sponsored welfare system is available, this could theoretically lead to a death via starvation and exposure! Laissez-faire economics is cruel in this way but technically dead people aren't considered unemployed. In a way, this can be viewed as a form of discrimination against people who cannot achieve the higher level of education (be it because of financial resources or mental capacity) that high-tech jobs require. However, this is also offset by the higher (3) wages that high-tech jobs offer over other jobs so the workers who manage to get the high-wage jobs can also be viewed as adequately compensated for their efforts.
There are probably many more revolutions waiting to happen and when they do large number of people will be made unemployed because of it. If history is any guide, as the agricultural revolution and the industrial revolution have shown, these same people will just find something else more (4) important to do, eventually. It's Adam Smith's free-market system at work here again.
References
[1] Lucidcafe.com: Adam Smith: Economists and Philosopher
http://www.lucidcafe.com/library/96jun/smith.html
I like your interesting analogies - I wonder if playing computer games will influence the leaders of the future?! I also wonder how lawyers would help us fend off the coming alien invasion, but I guess this wasn't really the point you were making. Good use of Adam Smith as a secondary resource.
(1) In a way, I think the government and to a certain extent, social advocacy groups play the role of the planner in video games with respect to public welfare. Interestingly, as corporations become more influential, the control of government is decreasing, and therefore I think it is even more important to have someone looking out for public welfare, since I don't think it's a by-product which would arise on its own. On the other hand, I certainly wouldn't want to live in a computer-game-type world where I had to depend on the benevolence and foresight of a single person for my well-being!
(2) Right, as long as a job "doing something else" exists. Another feature of capitalism is that advertising exists to create "new needs" which provide employment for displaced workers.
(3) I'm wondering what you mean by "this is offset by the higher wages that high-tech jobs offer". Do you mean that the cruelties of laissez-faire economics are offset, or the discrimination against those who cannot afford higher education, or the cost of higher education itself? I think perhaps you man the third possibility but it wasn't clear.
(4) I always worry about the individuals who are affected by such changes. Perhaps in the long run these people will find other work, but it could also be that statistical unemployment doesn't change but the nature of the work changes (for example, people who previously had secure, full-time jobs now have minimum-wage part-time jobs). This is one objection to utilitarian ethics - that although "on average" something could be said to increase the "good", the effect of the changes on specific individuals could be quite negative.
8/10