I'd be shocked to see 4k replace the market in general any quicker than the lifetime of current sets. And that's if there is negligible difference in price by then. It simply isn't a useful tech for the size of sets most consumers are buying and content will be spotty at best for an extremely long time. Hell cable and satellite have a tough time delivering any signal better than 720p as it is. Bandwidth is going to get a lot better before we see any change there.
I'm one of the most excited people on earth about 4K, but realistically, we're talking 2022-2025 before the 'average' set at Wally world/etc is 4K. And that's fairly optimistic. They are hugely more expensive to produce, and that's not going to change any time soon. In the day of 42" 1080p for $349/etc, it's hard to get joe blow to spend even $1k on a 4K set. And $1k for a 42" 4K? Maybe by 2019 or 2020 at the earliest.
And that's not even the worst part. The worst part is that broadcast/cable/satellite as you say won't be 4K ready for a loooooooooooooooooooooooooooong looooooooooooooooooooooong time.
The reasons are many, and with so many huge obstacles it's incredibly difficult for them to overcome.
(1)- Most areas of the country don't have good fiberoptic network connectivity, which is needed to pipe the kind of bandwidth even fairly compressed 4K needs.
(2)- Virtually all existing networks aren't even properly set up for 1080p.
(3)- Dish/etc satellite cannot do 4K with existing infrastructure.
(4)- Overcoming these and other problems will require the investment of many, many billions of dollars. Nobody is going to spend these billions when the market/demand for such products is nonexistent.
I honestly believe that we're looking at a repeat of Laserdisc with 4K tech. The parallels will be astonishing.
(A)- A great technology, but expensive, and initially adopted by only a tiny fraction of owners.
(B)- Shortly after launch, mostly forgotten and idle.
(C)- As better TVs start to become more widespread, and the costs come down, demand increases quite a bit, and it becomes at least a vibrant niche home theatre standard.
(D)- Replaced by something better.
That's what happened with Laserdisc. It officially debuted in 1978, but it was ahead of its time. Basically nobody had TVs that could do it justice, and content was next to nil. By the mid to late 1990s (until DVD killed it), it had become a centerpiece of any home theatre buff. Content was robust, and tons of amazing director's cuts, Criterion discs, etc were out there.