Early adopters who want twice the resolution as ordinary HD TV will have to pay dearly for it. The price tag for Sony's XBR-84X900 works out to 0.3 cents per pixel.
One hurdle for Sony to overcome: there's barely any video available that's shot in 4K, though there's a 4K YouTube channel, some movies and movie theaters are making the shift, and Sony's TV can upscale traditional 1,920x1080 HD video to 4K. Another hurdle: 4K resolution is too high to perceive unless you're sitting very close to the screen, by some measurements.