I mean, Queen Victoria died in 1901, and King Edward VII in 1910, so anything from their lifetimes is already "dated" to more than a century ago. However, I would suggest that from a creative standpoint mainstream cyberpunk is at least as rich as its steampunk subtype (it really can't be less, by definition). As long as our neuroscience trails our cybernetics there will be a wide frontier; we don't even have an AI yet, nor is one expected soon, so human-computer integration doesn't seem "TOO possible" to me.

I appreciate speculations appeal, have felt it in mainstream fantasy, alternate histories (including some steampunk) and time travelers carrying knowledge of blackpowder, railroads etc. to earlier centuries (again, as in Connecticut Yankee). My problem with steampunk, in the cases where I have one (which is far from all of them) is that when it requires invalidating scientific law and grafting a postmodern zeitgeist onto an age that preceded it by half a century or more it wrecks the verisimilitude for me. It's like saying, "what if JFK had been a Martian?" Well, great except we know he wasn't because a) we have his corpse and b) there are no Martians and never were. I don't require my fiction be possible, but I do require it be plausible; where steampunk accomplishes that I can enjoy it as much as anything else.