I make irritated noises at the idea, partly because of how sci-fi is relegated to genre ghetto, partly because the question's inevitable. The propaganda publishing-world answer is "no". A more thoughtful answer is "it depends on how you define science fiction."
I mean if you think of what science fiction usually means, it's wooden plotting and character, enormous breasts, story staring bug-eyed at some technical challenge (no water, disease, an expensive robot gone bad, space armada with unbeatable weapons) and driven by the grammars of other genres: action-adventure, mystery, fairy tale, gothic romance. This is obviously not what I'm after in talking about our own machineness. While I'd bet there are many novels yet to be written staring at the idea of our being machines...well, I liken it to the difference between tourists and residents.
You go to a strange city, you're struck by the landmarks, by what people wear and how they talk, by the width of the streets, whatever's strange to you. Live there for a while, or a lifetime, and you become blind to certain things (tall buildings, say) or you understand them with a depth and richness unknown to tourists (what it means, for instance, that people talk the way they do). You're A.J. Liebling, not Paul Theroux. And over the span of your life in a place, the features rise and sink and take on different meanings. The tall building is a landmark, is invisible, is an historical anchor, is a political controversy, is a proxy for powerful men you may or may not know or have dealings with. The way a woman talks is a novelty, a struggle to understand, a master to your clumsiness with the local language, a sign of a certain status, a souvenir of a time and place with certain meanings of its own, which may or may not be meaningful to you personally.
So with ideas like machineness. I don't think a novel staring at life's mechanical nature is going to be very much more interesting than a tourist's travelogue. But if artists can draw out the meanings and life of how we already understand ourselves, now, to be machine to some extent -- or if they can imagine a world that doesn't quite exist yet, but is conceivable in, say, the next fifteen years, or 50 -- and get to those depths and richnesses that you get when you really live with something and take it for granted, I think we'll have something very interesting.
And I guess that's really the question: Is it SF if the premise is "just suppose," and you're supposing something to do with science?
(There's a discussion on a related topic at LabLit, mostly to do with how "lab lit" -- fictions about scientists and doing science -- might be distinct from science fiction. They also answer my question by contrasting sci fi with "speculative fiction", at which point I wonder how much the label matters.)