4K monitors are all well and good, but I'm still concerned with the delivery mechanism to get the data to home users. Even in 2012, the amount of compression used in puny 1080 is pretty horrendous. Read what ZDNet writer George Ou says in his essay Don't Believe the Low-Bit HD Lie. The HD you see on most cable systems or downloads is very highly-compressed HD; Blu-ray can be pretty good at high bitrates.
My fear is that if and when we get 4K on cable and/or broadcast, it's going to be compressed so badly, it'll look like crap. 4K is just a number. Guaranteed, by the time iPhone 6 or 7 comes out, they'll have it in the phone -- and it'll look awful. Still technically 4K, but not good pictures.