8K TV is slated for 2025.
The current cameras use four 2.5" CCDs (2 for green).
http://en.wikipedia.org/wiki/Super_Hi-Vision
That doesn't mean we'll see it or that it'll propagate into theaters, or that it'll be commercially viable at that time- the French had monochrome HD in the late '40's. It's taken more than 20 years to get the US to the point where HDTV is common, and it still doesn't have the lion's share despite lower TV prices, larger screens and lack of repair options for many tube-based sets. The bulk of people aren't going to upgrade simply for higher resolution. HDTV came at a time when several things were convergent- spectrum reshuffling, LCD/Plasma panels and a significant drop in the price of the sets. If 3D entrenches itself before then, it'll be a huge barrier to entry to getting sets out to consumers.
While the spectrum issue is slowly becoming moot for a lot of people, the US sold a metric buttload of converters.
(For what it's worth, I spent a fair amount of time dealing with the HDTV specs pre-standard when I worked for Gannett, who owned ~24 broadcast TV stations at the time, though I spent more time on the possible utilization of the sidebands during low-activity broadcasting than on the economics as it was a USG mandate.)
If you'd seen the wrangling over the CODECs and standards for HDTV, which made the DOCSIS stuff for our cable division look like a walk in the park methinks you'd have far less optimism.
The market (consumer) doesn't need more resolution- the only potential pushers are the equipment manufacturers, and they have a lower chance of achieving a refresh this close to HDTV's general acceptance than they'd like to think.
Paul