First, a note of scepticism. The first industrial revolution didn't create lasting mass unemployment, so why should the next? And Keynes' forecast (pdf) that rising productivity would lead to mass leisure was also slightly off-beam.
One reason for this is that as we get richer, our aspirations rise and so demand rises to create jobs; the reason why Ed Miliband can talk of a cost of living crisis without looking a fool is that we compare our standard of living to 2007's, not 1907's. Another reason is that rising productivity affects relative prices, not just absolute ones. It cuts the cost of goods relative to services. Some things, then, would remain expensive; a century ago, upper-middle class people typically had several servants. And let's not talk about housing costs.
Let's though, put this aside. What Frances is getting at, I suspect, is that in a wealthy economy, very many skilled people would be able to retire early. Such an economy would face the problem not (just) of what to do with redundant unskilled labout, but how to retain affluent skilled people.
Here, we can - coarsely speaking - think of two types of people.
Type I are those motivated by status concerns: bankers who want a bigger bonus than their colleagues, bosses who want more people to control. These will keep working/rent-seeking however absolutely rich they are.
Type II are motivated by intrinsic goals such as self-actualization. These would want to give up unfulfilling work once they can afford to.
There is already a tension between these types. Many professionals of around my age and younger downsize, step off partnership-path careers, leave to work for charities, become part-time consultants or singing teachers and so on. In a more abundant economy, many more would do so.
This would pose a problem for status-mongers, who need skilled colleagues and underlings. One solution to this tension would be for them to cede power to the type II types, so they could achieve more personal development - or alternatively, for them to go out of business to be replaced by more egalitarian workplaces. Gradually, capitalist-type firms, with hierarchy, profit motive and alienated labour, would give way to communistic organizations with equality and less alienated labour, through interstitial transformation. "Self-realization through creative work is the essence of Marx's communism" wrote Elster.
Marx thought a socialist revolution would happen only after capitalism had massively raised productive potential: "No social order is ever destroyed before all the productive forces for which it is sufficient have been developed." Or as Cohen put it: "What makes a successful revolution possible is sufficiently developed productive forces."
Central to this story is that there are workers who are necessary to the productive process but whose needs are not met by that process. Revolutions are made not by the most wretched people, but by those who have the power and motive to effect change. If Marx is right, it is success that will kill capitalism, not failure.