The Postmodern era: Did it happen? There seems to be some struggle to identify the novelty of postmodernity here, but I would suggest it is to be found in an area which seems to be relatively neglected so far in this thread - aesthetics. Pace Jameson, you have a few standout features: the prevalence of pastiche as an aesthetic form, the preponderance of irony, the increasing indiscernibility of 'high' and 'low' culture, the weakening of 'historicity' (the inability to locate ourselves in an arc of time, you simply get dislocated and fragmented temporal repetition), the 'waning of affect' (a 'flatness' of emotional tonality, where nothing surprises anymore, and everything is approached with ironic detachment), the suspicion of 'depth' and the valorisation of 'surfaces' in our aesthetic topographies, etc, etc
Taken in this way and as a set of feature relating to the sensibilities with which we apprehend the world, I'd say it's hard to deny that postmodernity - at least taken as a tendency or set of tendencies - has definitely had its time. The issue of the 'waning of affect' is one of the more questionable theses, and it's arguable that there's been a heightening of affective importance in recent times, but otherwise the rest of the list is pretty on point I'd say. On the other hand, there is the consideration of just how euro or Anglo-centric the notion is. Like, how much of this characterizes the sensibility present in Asia, Africa, or South America for instance? Is postmodernity a phenomenon more specific to the global north? I suspect so.
That all said, of all the features involved, my own winner for the most significant one is the waning of historicity. This goes hand in hand with the basic neoliberal premise that 'there is no alternative' (TINA) and the notion of "capitalist realism" - that there is no real future. That's been disrupted somewhat by the slow rot of the American empire and the rise of a new bi or tri polarity on the global scale (China-US-Russia), but even then you get this feeling that at stake is the rise of a new hegemon which only a few tweaks here and there (slightly less liberal, still capitalist as all hell). That we seem to be unable to locate ourselves in time (and space too!), is a big one. Jameson calls it an inability to engage in 'cognitive mapping'. More and more I find Benjamin's reflection on history to be more pertinent than ever:
"A Klee painting named ‘Angelus Novus’ shows an angel looking as though he is about to move away from something he is fixedly contemplating. His eyes are staring, his mouth is open, his wings are spread. This is how one pictures the angel of history. His face is turned toward the past. Where we perceive a chain of events, he sees one single catastrophe which keeps piling wreckage and hurls it in front of his feet. The angel would like to stay, awaken the dead, and make whole what has been smashed. But a storm is blowing in from Paradise; it has got caught in his wings with such a violence that the angel can no longer close them. The storm irresistibly propels him into the future to which his back is turned, while the pile of debris before him grows skyward. This storm is what we call progress" (Thesis IX, Theses on the Philosophy of History).