I will be long dead before the 21st century is over, let alone properly evaluated.
But I am still willing to stick my neck and foretell what the characteristic fiction of this century will look like --- and what it won't look like.
Oh sure, there will be plenty of spy cum adventure action dramas that replace battles with Russian communist spies with tales of blue-eyed blondes fighting off dusky Arabs and sinister yellow perils, but really - isn't this all a bit 19th century-ish ?
No, a truly 21st century genre fiction will deal with the striking events of its own century : and that means denier-wars and global warming / climate change.
From the Ayn Rand side of things (and let's face it: with the quality of ghost-writers today, Ayn Rand dead might write more readable fiction than Ayn Rand ever wrote alive !), there will be stirring tales of "The Sons of Liberty" fighting off sneak attacks from "Eco-Terrorists" trying to destroy the oil wells that dot the warm blue waters of what was once the icy Arctic.
But from the quality side of the literature bazaar : say upmarket Atwood, we should expect the same tale of oil wells at the North Pole , but told this time as a century battle between that notorious globe-raping gang, "The Cut'n'Runners Boys" versus those plucky Eco-PIs, "The Sustainer-Gals" .
Now - admittedly - we are already 1/8th our way into this century, with no real sign that either type of book has become prominent in what is left of our bricks 'n' mortar bookstores.
Perhaps there in lies a sterling literary and business opportunity for veteran (and budding) fiction writers all over the world ...