As I can tell for germany: Most regions here switched from analog to digital tv-broadcast (DVB-T) recently. People had to buy a new TV-tuner for this. They will not understand, why they have to buy new equipment again. Additionally, tv-broadcast with HD is nearly nonexisting. I know about AnixeHD (A sattelite broadcast I believe) but most normal satellite, radio-wave and cable broadcast delivers no HD. Even if you get HD-signals, nearly no content is in HD, thats only some shows like Desperate Housewives and Greys anatomy or some documentation, that re in HD. So I think, here in germany it will need some more years, before HD-adoption becomes relevant. My guess is: not before 2010.