Although I don’t disagree with any of this, and although I’m a committed fan of globalization, I’m skeptical that a government guarantee of health insurance, say, or a dollop of wage replacement insurance for those too old to make the transition into a new career would do all THAT much to blunt the incentives to upgrade skills. Moreover, I’m increasingly convinced that lack of health/economic security is exerting at least some negative impact on the ability of Americans to fully partake of the so-called “Ebay economy.”

I guess what I’m saying is that I suspect to a substantial degree we can have our cake and it eat it, too: Sam’s Club protections combined with Brave New Economy opportunities and efficiency. I reject the notion that we must choose either/or because it least appears to my eyes that a number of other places (New Zealand? Ireland? Canada?) are rejecting this false choice to their great benefit.

“Many people will surely be temporarily upset when the shifting incentives of the global market upset their usual patterns of work and life, very much as people in the Rustbelt were upset by the process of deindustrialization.”

Is this really the analogy you want to use here? First of all, the rustbelt hasn’t recovered!! There has been no upswing nor is there any prospect of one. Second of all, you can already see some (albeit small) signs of populism ther – the election of Sherrod Brown being the most glaring.
Lastly, yes, when people become interested in making government bigger in order to effect large welfare programs you have populism. Are you being deliberately obtuse here or what?

What of middle class Americans with families to feed acquiring the skills needed to increase their income when their job gets replaced by a machine? Do we have a definition of Libertarianism here? Or does technology lack the appeal of the yellow peril?

I think we have a definition of Libertarianism here.