I think it is worth pointing out that they appear to be proposing two UHD channels plus multiple SD channels on a single RF channel. Maybe we (or maybe just me) only reasoned that it wasn't possible to do while maintaining sufficient quality to prevent the picture from looking worse than HD. There is technology built into the standard that should insure that content doesn't have to be re-encoded to put in "bugs" (logos) but there's still the issue of how do you mux all that together without having to engage in adaptive encoding?
Will there be any UHD content for them to broadcast?
I'll ignore the proposition of a UHD Antenna TV because the idea makes my head hurt.
Surely most will drop broadcast TV like a hot potato if all DTV broadcasts are smooshed to SD and they're not poised to upgrade.
I'd also like to call out those who suggest that the tuner dongle is going to be $30 a pop. The current ATSC 3.0 USB tuner dongle is $1,000 and while someone (I think it was Sinclair) has offered up $1 million in subsidies, that won't go very far. The Gubmint was prepared to pour in over $1.5 billion into the DTV converter program.
Some have suggested that the converter boxes will simultaneously support multiple TVs but I'm dubious about the infrastructure required to handle it.