The 4K standard is already here in the home projector space, more or less. Sony makes a $25k projector that's native 4K, while JVC has several models with the "e-Shift" pixel upconverter that puts 3,840x2,160 pixels on screen even though the LCOS chips are 1,920x1,080 pixels. A case can be made for 4K with larger screens at home. At the moment, though, light output limits screen size far more than resolution. For home projectors, let's just shrug and ask, "OK, why not?"
But with televisions, 4K is stupid. Stupid, stupid, stupid. For every one of you thinking you'll rearrange your living room to sit closer to the screen, I'm positive there are thousands of others who wouldn't (or wouldn't be allowed to).
Sure screen sizes are going up, but how many of you are really going to put an 85-inch screen in your home, and sit close enough to it for 4K to matter?
Don't believe me? Get a chair, and sit close enough to your TV so you can just see the pixel structure. Now watch an entire TV show like that. Now convince your family to do the same.
There's this feeling of inevitability with 4K, like because we can do it, we will do it. I just wanted to point out early that regardless of what the marketing and hype will say, you don't need 4K.
So if someday there's a choice between a 4K 80-inch OLED and a 1080p 80-inch OLED, sure, pick the 4K. Move a little closer to it and presto. But inevitably there will be even smaller 4K displays, and unless you're sitting on top of them, there's no point.