Until that kind of connection is the basic norm in the major areas of the world, we are nowhere near this kind of HD download content.
This kind of infrastructure and net speed needs to be nationwide before this service takes the lead. For example, the majority of the UK doesn't even have cable connections installed, what chance do they have getting fibre optics.
However, I will concede that downloadable HD services will spur the industry on to install & develop cable/optical net services.