Tim's post, like many of his, is a concentrated bundle of ideas and connections. In this case, I both deeply agree with parts of it, and also disagree with others.
(1) Marx on machines is pretty essential for those trying to think through non-humanist understanding of relations. Switches from one mode of production to another mode of production comes not through some sort of economism, but rather as a way in which material processes are both shaped and simultaneously shaped by humans. In other words, humans are one part in the creation of history (in Marx a particularly privileged part still, but maybe not a necessarily privileged part), but so are tools, technology, machines, and the inorganic body of nature (sometimes in Marx's writing the natural world seems passive and inert, a mere resource to be used by humans. At other times nature is depicted as a fully engaged process and producer itself, one which is fully enmeshed with the artificial world. In other words, in some nature exists, in others we have a view of ecology).
(2) This is why Marx claims, in a footnote in Capital, that "Technology reveals the active relation of man to nature, the direct process of the production of his life, and thereby it also lays bare the process of the production of the social relations of his life, and the mental conceptions that flow from those relations". This is one my agreements with Tim, who writes:
Marx says that when you have enough machines, in particular machines operated by other machines and making machines, you get a jump from a quantitative increase in machinery into the realm of the qualitative, into fully fledged industrial capitalism. Some kind of jump occurs.Yes, and all of that is important. This new type of capitalism emerges because we have a new mode of production. Not just a production of economics and things, but an entirely new mode or relation, a new mode of life and the reproduction of life in the full ecological understanding of all of that. This is why it is important to grasp a history of these machines. Or at Marx clarifies earlier in the footnote I cited: "A critical history of technology would show how little of the inventions of the eighteenth century are the world of a single individual. As yet such a book does not exist. Darwin has directed attention to the history of natural technology, i.e. the formation of the organs of plants and animals, which serve as the instruments of production for sustaining their life. Does not the history of the productive organs of man in society, of organs that are the material basis of every particular organization of society, deserve equal attention?"
(3) For Marx, individualism in humanism has been displaced, but a certain human causation continues, one he doesn't seem entirely willing to break free of. However, at the same time his writing also freely identifies non-human actants as being full actors. For 'the machine' reaches a certain point where it no longer is run by humans, but rather uses humans as appendages to the machine. Thus, in my dissertation, I explore how we become appendages to the machine. How the birth of a disciplinary subjectivity arises within the assembly line (understood both technologically and managerially) of the Chicago meat-packers. And how a whole complex of forces bring us to that moment (barbed wire fences, monopoly capital, railroads, refrigerator cars, mono-culture agriculture, specially breed animals, etc.). Marx's view of modes of production is absolutely essential for me to think all of this. At the same time, it is also essential that accelerate Marx's posthumanist tendencies, rather than his humanist ones.
(4) Time mentions that it is surprising that we don't have more Marxists engaging with speculative realism and new materialisms, but I think he is doubly incorrect in this part. First, I think we have a lot of Marxists dealing within those terrains, but not particularly older and more established Marxists (though Levi might be the only OOO Marxist out there). Second, it isn't that surprising that so many Marxists would be turned off when so many of those people engaging in speculative realism and new materialism seem specifically anti-Marxist (like Ian's position, Tim's own recent aside about how he isn't a Marxist, Delanda's strong rejection of Marxism, etc). But I don't think Tim really means Marxists in general here, he probably has certain Marxists in mind.
In the end, I think we will probably see increasingly larger number of Marxists engaging new materialisms, and new materialists and realists of all stripes also engaging Marxism. Or at least that is how all of this has always worked within my head.