4K (a.k.a. ultra-HD) is the biggest buzzword in video right now. 4K video is so-named because it packs in four-times as many pixels as the HD picture you're now used to. Netflix is making a huge push to ramp-up it's 4K video library (as well as trying to figure out how to stream it to you), and ultra-HD is the next era for TV manufacturers as well.
Samsung has always pushed the envelope with HD displays. These TV's are difficult to manufacture on this scale and require a tremendous amount of re-engineering and innovation each time they go bigger. And while a TV of this size will certainly not enter mass-production for quite some time, each iteration makes the manufacturing process just a little easier and a little cheaper to help bring down the overall cost of the sets you can purchase.
This model will be custom-order only with a price tag in South Korea reported to be somewhere in the range of $150,000, and they will only be made available in South Korea, China, Europe, and the Middle East to start.
Wondering who would buy one? The Associated Press claims Samsung has already received 10 orders for these TV's from the Middle East.