It never fails to amaze how "old" these systems are by the time they become common palace. No doubt 16k already exists in some lab situation
All technology is "old" by the time it reaches mainstream. That's the way it is.
Even computer parts that have literally rolled off the production line and into a computer near you is already at least one generation, sometime two, behind what Intel/AMD are currently working on.
I dare say 20k, 24k or even 32k are all potential future technologies, though this presumably puts us at a stage where we'll be able to literally see sweat dripping off everybody at the Olympics but the bigger question is, how effective is that going to be on most domestic TV screens of 26-54"?