You're not going to buy a 4K TV this year. There's one reason to buy into 4K this early--it's shiny and new--but there are tons of reasons not too. It's too expensive. There are no 4K Blu-rays or streaming options. There's no 4K cable service. Sit far enough away from your TV, and you won't even be able to differentiate 1080p and 4K sets. You shouldn't care about 4K TVs yet. But you should care about 4K computer monitors.
ViewSonic and LG both had prototype 4K monitors to debut at CES this year. Both are clearly a ways away from a retail release, but ViewSonic hopes to have theirs out on the market by the end of 2013. Unlike 4K TVs, higher resolution monitors offer some real practical benefits. We sit closer to monitors, so individual pixels are much easier to discern. More screen real estate is a major boon to productivity. And scaling the operating system, like Apple does with its "retina" displays, results in much sharper text.
ViewSonic told me that their 32-inch, 3840x2160 panel is LED backlit, though its thick housing resembles bulky older CCFL 30-inch monitors like the Dell UltraSharp U3011. That's not unusual for a prototype; the final model will likely be slimmed down and given a few features notably lacking in the unit that was on display.
Currently ViewSonic is pumping images to the 4K display with two DL-DVI cables, but the final version will probably include DisplayPort (which supports resolutions up to 3840x2160) and HDMI (which maxes out at 4096x2160). A ViewSonic rep said that they'll probably throw in VGA just for kicks, so I expect the usual range of connection options to be on-board.
Since LG supplies panels to Apple, Dell, and tons of other Korean monitor-makers, I asked ViewSonic if their 32-inch 4K display was using LG technology. They said no, and that yields are extremely low on 4K panel production. No surprise there, but it means the prototype model is painfully expensive--it cost ViewSonic somewhere between $15,000 and $20,000 to produce. Good news: the final unit should be cheaper.
Viewsonic's rep told me they hope to get the cost down to $10,000 for a consumer release. Okay, that's still way too expensive for a monitor, though the 4K monitor is squarely aimed at serious photographers and video editors. But given how dramatically monitor prices have dropped in the past few years, it shouldn't take long for yields to improve and for 4K monitors to drop down to reasonable prices. LG may be able to help with that: Details are light on their 4K prototype, but when they start producing panels en masse, we can hope for 4K to become the new 1440p. In the meantime, companies like Monoprice are dragging 2560x1440 monitors into the affordable mainstream.