Interesting CES covering from The Register this year, who as always show a cynical disregard for technologies that nobody has actually asked for: It's 4K-ing big right now, but it's NOT going to save TV.
Virgin Media still only broadcasts all its HD in 720p and, as far as I'm aware, has no plans to increase this to 1080p. Sure, your TV may present it as 1080i, but the next step for VM and Sky would be 1080p, and even the most-lauded Netflix 4K content is actually currently upscaled. My Sony TV's Freeview channels occasionally are received in 1080p (notably some BBC content).
I'd expect Sky to launch and shout a 4K offering at some point, they've already done some trials, but I can't honestly see an appetite from the consumer yet except those hapless few who have to have the latest-if-not-greatest to impress the neighbours.