That's revisionist history, ludicrously so. Marx never foresaw anything of the sort. He believed firmly in the labor theory of value, and as such all economic power derived from human labor, not from mechanical power. Communism was about combating the concentration of economic power in the hands of a few people who owned the means of production, at the expense of the masses who provided the labor (and hence the real value).
It is not very hard to re-frame Marx in terms of the knowledge worker, where the owner of the means of production like the [e-tail site/online bank/search engine/social networking site] exploits the individual developers who produce the system but alone are insignificant and replaceable leading to a race to the bottom where providing the labor is greatly underpaid while stock owners and other capital holders make off with the profits. That does of course not exclude the possibility that capital owners will pay off unique individuals and start-ups that threaten to shift the competitive landscape or compete with the existing companies, but more of a global mutual interest among all companies to depress wages.
Even in the absence of formal collusion it's not hard to reach a form of unwritten understanding in direct and transparent competition of substitute goods. For example on the way to work there are two gas stations quite literally across the road from each other, if one drops the price of course the other will follow. So what makes them profit most, both high or both low prices? Now apply the same to store clerk wages, of course neither has an interest in raising the general wages. It is really the same when you see Google/Apple/Microsoft/whatever involved in anti-poaching agreements, surely they could just poach back but it'd raise the wage costs for everyone so better if they don't.
I do agree though that he thought the actual value lay with the labor, not the machinery but I guess you can equally apply this to software, doesn't really all value of the code stem from the one who developed it? Granted, he got paid for it but whether that pay is fair is another matter. Remember, Marx never claimed the workers were forced to work anywhere at gun point. What he said was that all the choices were bad ones and workers were exploited no matter who they worked for. It's not like market economists dispute that companies would lower labor costs if they could either, they just refuse to do something about it. If the supply and demand don't add up to a wage you're comfortable with do something else.
Of course we won't run out of jobs as such, but when there's more people wanting jobs than there are jobs, real wages start trending downwards as workers undercut each other. The relative wealth between those with capital and those who work for a living diverges and it becomes harder and harder to join them as their holdings increase faster than any savings you can make. As long as human labor remains essential to the function of society, we can still unite and strike for higher wages though. If we're no longer essential and the system runs on robotics, software and a few scabs until we go back to work, well then we're in deep shit.
