In consumer 4K videography, hybrid mobile devices (read phones, tablets and low-cost still cameras) will dominate the market mainly because of the reason of economy of scale. Take the Samsung Galaxy Note 3, for instance, it's 4K video pipeline consists of a 13-Megapixel Sony camera-sensor module, shared not only by its Galaxy S4 cousin but also by numerous Sony own handsets, and more than a few other brands and models. The OS is more or less off the shelf and free. The firmware that enables the Note 3's 4K video may be designed in-house but the Snapdragon 800 CPU and GPU are also shared by yet numerous brands and models. In short, the economics of insanely high-volume mobile devices allow several manufacturers to mix and match components that would never have been feasible if they had had to make on their own.
In contrast to the mobile devices sold worldwide, how many digital cameras are being sold nowadays? Though the camera manufacturers themselves have also been doing the mixing and matching of components from other suppliers as well but neither the scale nor the extent of it has not been or is ever going to be comparable to what the mobile device manufacturers have been doing.
In a few weeks we are going to have another phone to compete with the Note 3 on 4K, Acer Liquid S1, which in all likelihood will have a lower price but yet unknown 4K video quality. On the still camera side, the closest thing to consumer 4K video is maybe Canon 1DC and the soon to be released Blackmagic Production Camera. Neither of which can be called affordable nor user friendly. On the camcorder side, the only options are US$ 4,000+ JVC GY-HMQ10 and US$ 4,500 Sony FDR-AX1. Neither of which again can be called affordable nor pocketable.
I have no doubt this new Sony in particular will shoot better 4K image than any phone of this year or next will but does this really matter to the majority in the world of media consumption? One thing I can be pretty sure of is the new 4K Sony will never enjoy the popularity or sales on the level it's ground-breaking cousin HDV format HDR-FX1 did when it came out almost a decade ago at even higher prices in both then and today's dollar terms. The world has changed folks and we move on.