It will be for the same reason that 1080p was, there's a home cinema standard behind the screen resolution which will eventually be in every living room around the world and the investment into 4k panels will drive the cost down which is has done massively already.
Still, looking at 4K monitor, TV tech and GPU horsepower, it is still too niche. 4K adaptive sync monitors are too few, and 4K gaming on 27-28" isn't even an option for some gamers who would want 32"+ 4K gaming as a minimum.
There's 32"+ 4k monitors on the market, I just got one, using native res in windows 8.1 is fine for me. I'm not sure how much adaptive sync means to the average gamer, I personally don't really care enough about it to let it swing a monitor decision.
Windows DPI scaling is still not A+ which means outside of gaming, it's not as pleasant to use a 32" and below 4K monitor for productivity as say 1440/1600P or even a 34" 3440x1440.
If you have good eyesight then 32" is fine, windows DPI scaling is naff though and hopefully it'll be fixed in Windows 10 and patched in win 7/8 before long.
Quite honestly I find it hard to believe that OLED offers the kind of gains in IQ you're talking about with respect to something like an LED IPS panel, but then I've not seen them in real life. I have no doubt they're better but surely we've entered the realm of diminishing returns on panel quality already?
Res is less important for TV and more important for gaming, anything 3D has to be rendered to an approximation so screen resolution is a bottleneck for image quality in a more significant way than it is with TV, Aliasing being the primary source of bother but also things like the filtering of textures at acute angles. I find it hard to believe that OLED @1080p provides a better gaming experience than 4k LED IPS, although that is a highly subjective statement so each to his own I guess.