Vinge's certainly talking about the emergence of such an entity, in his original paper on the Singularity. He's talking, at least in the initial parts, about a "hard-takeoff" singularity, something that happens in a few years, months, or "perhaps in the blink of an eye": a machine (or cybernetic, or biological-posthuman) intelligence is created, and quickly creates a better machine/etc intelligence, which creates even a better one, an intelligence which "would not be humankind's "tool" -- any more than humans are the tools of rabbits or robins or chimpanzees", so that "the human era is ended".
It's worth noting that his prediction was not "2030" -- it was "I'll be surprised if this event occurs before 2005 or after 2030". So we are already in fair-game territory for the Vingean Singularity.
I think this is a seminal, critical, beautiful essay. It originates one of the notions which has been most inspiring to me as a science fiction writer. I also think it's largely bunk. (It's brilliant the way a brilliant, well-intentioned, unwitting Le Guin villain is brilliant -- someone with great intellectual talents for whom certain things are simply invisible.)
Perhaps a Vingean way to say this would be that we live in the Slow Zone -- one reason I think that A Fire Upon the Deep and A Deepness In The Sky have a much richer, deeper, truer take on the Singularity than his paper does (a very common phenomenon in my experience -- we are often led by the structure of writing fiction to say much truer things than we can speak plainly).
What Kurzweil are you referring to? What I've read of him is The Age of Spritual Machines, and my reading of that is that it does *not* suggest a hard-takeoff, singular-event, blink-of-the-eye Singularity, but rather precisely the kind of exponential growth I'm talking about where there is no undefined y for any x. The book is full of funny little interludes where Kurzweil interviews a fictional character living at various different decades. By 2100 she has merged with the entity which in 2010 was her PDA and in 2080 her lover, or something like that. Kurzweil keeps asking her things like "but hasn't some cataclysm transformed anything now? Aren't you slaves or emperors now?" and she keeps saying "Ha ha -- whatever. Shit, I'm so behind on my work, and I have all these patent litigations I'm embroiled in... sigh. I'll have to instantiate several extra bodies this weekend or I'll never get *anything* done..."
To her, it looks like a smooth curve. She didn't notice the Singularity. If anything she's still looking forward to one, even if her specific criteria might be different from the ones Kurzweil would offer if forced to pick a date.
I'm familiar with the multiple Singularities mostly from Charlie Stross, and as I recall they were something like spoken language, written language, agriculture and pastoralism, modern capitalism, digitalization, and (coming soon to a universe near you) P=NP. The issue here is not "influential inventions" -- it's ratcheting technologies creating irreversable changes in modes of human life. Once you have integrated one of these technologies fully into your society, you can't abandon it without killing off 90% of your population.
But dating them is arbitrary. At the moment that early Fertile Crescent merchants started doing preliterate inventory tracking with symbolic ceramic items, or that someone symbolized *those* into marks in wax or clay, or that someone started broadening the use of them from pure financial recordkeeping to make more general notes in the margins, perhaps choosing a set of the symbols to represent a human's name, or that the king decreed that the set of symbols representing *his* name be engraved on a tablet, no irreversable change had yet occurred. The wheel and the steam engine were not on Charlie's list, but Incan wheeled toys and Greek trick steam engines show that those weren't irreversable singularities at the moment of invention either.
Much like the digital age, the integration of such technologies into society is a long, slow, locally random process. And these singularities (the aphorism asserts) overlap.
The metaphor here is not Singularity as asymptote, a moment which changes everything (that thing which no exponential curve has one of). It's really more the Schwarzchild radius than the center of the black hole -- it's the point at which you can't go back.
So that's one sense in which the aphorism might be true (and you do know, right, that I come up with the aphorisms first and then figure out how they're true after you all pick on them?) -- there is always some irreversable technological change in the process of being dreamt of, iteratively developed, integrated and consolidated. It's only on history quizzes in school that fundamental technologies have singular inventors and dates.
So let me go do some day job work now, and then I'll talk some about why I think we live in the Slow Zone.