I don't think this distinction is going to matter much to people.
A great many keep misuing the suffix "p" for any common monitor resolution (e.g. saying "1440p" for 2560x1440, or "2160p" for 3840x2160). It correctly denotes progressive-scan television resolutions, and once you get beyond standard definition, the only two valid "p" resolutions are 720p and 1080p. Which are both different from non-TV signals with the same resolution (i.e. 1280x720 over DVI or VGA is not the same display mode as 720p).
Well, 3840x2160 is exactly 4x 1920x1080, 8,294,400 pixels, but really buying a 4K TV right now just because it is 4K when the television stations only broadcast in 1080i or 720p is a waste of money. That being said UHD TVs are a good buy if you have to replace a main TV as they are, in some cases, even cheaper than FHD models from the same manufacturer, and the upscaler in quality models does make a difference, not to mention the LED backlighting means the TV consumes far less power and produces less heat than a CCFL backlit one. I do wish they would be required to stop calling them 4K displays, instead call them 4X UHD, but as far as a television broadcast goes if the standard is UHD 3840x2160, it doesn't matter if you watch it on a UHD or true 4K panel, it's going to have to be displayed at 3840x2160 to prevent distortion, which means black bars on a true 4K display.