Carlton Bale has published an excellent chart and explanation that sums up 4K TV’s problems in a nutshell: at some distances and screen sizes, even the difference between 720p and 1080p to the human eye can be negligible, and this is even more true of 4K. To get any benefit out of a 4K TV, you either need to have a very large screen (the benefits begin to become apparentâ€”barelyâ€”at around 50 or 60 inches), be sitting very close, or both, and small differences like this might appeal to true home theater enthusiasts or videophiles, but it’s going to be a hard sell for the average consumer.
Why do we assume 4K displays will be mainly used as TVs?
Update 2012.06.29: LG is researching 60-inch transparent flexible 4K displays. Reminds me of the curved transparent computer workstations in Avatar.