If your in Auckland, then tune your widescreen lcd/plasma to Juice TV on UHF, its comming thru on mine without any problems and in widescreen, very clear too as we have direct line of sight to waiatarua. picture is not stretched at all, its appearing exactly how it would when I view it thru sky. However if you view Juice TV on an old 4:3 tv then it will appear vertically stretched. Reason for this: they use an old Pace sky decoder locked to Juice tv up at the waiatarua broadcast station, they have 16:9 set in the tv settings on the sky decoder, it used to be 4:3 pan scan but they changed it for some reason or another.
Analogue TV can easily be broadcast in anamorphic but for the exact reason you've listed it's not. A large % of people watching analogue broadcasts only have 4:3 TV's so are unable to watch the anamorphic broadcasts. If TVNZ or TV3 tried to do this there would be outrage!