Re: Content content content....
Well, it is theoretically possible to broadcast 4K over terrestrial, using DVB-T2 and the HEVC codec; the BBC have run tests of that. But longterm, it's extremely unlikely to happen because of the bandwidth squeeze. It's going to be hard enough to maintain the current level of service as the mobile providers snaffle up more of the space as it is...
On satellite, all the major platforms have plans for 4K and there are already some test streams on Astra. Of course, you're going to need 4K receivers for that too, which I expect we'll see more of over the coming year or so - especially once the DVB group has firmed up specs.
Astra for has quite a few new satellites coming on stream, so there should be a reasonable amount of capacity for 4K transmissions.
As ever, you can probably expect that the majority of these will be premium services from subscription companies like Sky, with maybe the odd "Oh wow look at the Olympics in 4K" type of thing from some PSBs.