Dell has produced the first 4K OLED 30" monitor. A snip at US$5,000. It looks like the OLED panel is made by LG and the manufacture of these things is getting more cost effective. The price and size of these screens should reach affordable soon.

Link

Very sexy technology, I'm sure one day it will become the norm. I didn't see the power consumption mentioned, I would hope that it's more efficient than the current LED back light technology but right now we can only guess.

Of course this will add a huge chunk of cash needed for a PC build with a nice graphics card that can handle 4k at a sensible FPS. That's progress for you, it cost a lot.

I see that with this new tech we get back an old problem: Screen Burn-in. I ruined my parents' less than a year old RCA console TV the year I got Pong for Xmas. It sounds to me like screensavers will be making a comeback once this level of technology becomes mainstream.

By the way, I REALLY want one of these!

Having an OLED screen on my Galaxy S5, I have first hand issues with burn it. It is mild and only noticeable on a totally white (or bright) screen.
I have no such issues on my old HTC One M7 which had an LCD 4 screen.

The main difference is contrast ratios and blacks. Unless you have them side by side, they're both very good and you'd never notice.