The time frame between the switches in different media formats has gotten shorter and shorter between formats, because of the accelerating rate of innovation.
BD struggled to catch on at all, and is still not purchased by the majority of people, in terms of marketshare and demonstrated sales. There is also research to suggest that the human eye can't even perceive differences between 1080p and 4K res, especially not on a display size that most people would own at home.
3D is still studdering and was dismissed, overall, as 'not necessary' at home, and largely because there was a lack of content, high disc/hardware prices, and a poor marketing/education campaign. Most people when asked, claim they can't see the difference, or don't care whether there are differences between BD and DVD, and are content with the latter (as shown by DVD sales).
Just as we have the current format war between what's left of recorded media and the rapid onset of the industry to adapt instant media in the form of streaming, downloads, clouds, etc, this, if launched, will turn into another 'niche' product. Perhaps the projector or large screen (70+" inches) display owner will actually see a difference and want to adopt yet another standard.
If, a 'new' BD has a resolution that can be displayed on a 4K display without being upscaled (in effect replacing BD's current resolution, without introducing yet another recordable 'format' with another name), and if discs remain at current prices (not at the premium at which BD started out years ago), then who knows.
I think given the relatively short period between when consumers have had to replace all of their equipment, the launch of 4K is nothing more than the manufacturer's way to have 'another thing coming down the pike', which they always do.
For the hardcore PQ/AQ and HT enthusiast, there will always be a preference for recorded media, as long as streamed/downloaded content is limited in PQ/AQ, and because most want a tangible product for their collection. That debate is raged every day. Plus, all movies ever available on DVD will never be switched over to this new format, so as long as that is the case, one format cannot totally replace another quickly-either for software or hardware...but I am sure there will be a niche.