Looks like it's been recorded in >30 or >60 fps and then slowed down as well. Can't imagine the bandwidth and storage that'd require. Would eat through mechanical hard drives faster than I eat through SD-cards. :P
While I won't lie and say I wouldn't love to have 4K, it's mostly the "I want this"-thing. I've been talking and hugging 4K for years as the 'perfect resolution'*. And I still think so. I don't think I'd like to move beyond that in a reasonable timeframe (20 years?).
I think I'd have much trouble telling the difference from 1440p and 4K, and I think I'd just suffer at those resolutions. Ie, graphical horsepower would not be up to par. 1440p at 24", or 4K at 32". Then I'm good.
* = Each pixel in 720p becomes 3x3, 1080p becomes 2x2, so it'd scales 'perfectly'.