[Ghitulescu]

It's highly off-topic, but I'll try to explain you once and for all:

Long before BD was launched, there were HD TVs and HD transmissions. I live in Europe, I don't know how the things were in the States, or in Japan. To sell those TVs that had an awful image with SD aerial/cable senders, most manufacturers had a proprietary device that fed the TV with HD images (Philips has one, Sharp had another one, Samsung too, Sony had the prototype - cartridged Bluray, and so on). They were MPEG-2. Some shops ran HD shows/loops from satellite, all of them being at that time MPEG-2, and sent using the old DVB-S protocol. Several years later, the same demos were put onto the Bluray disks, as now a unified standard exists. That's the story with MPEG-2 and HD. After movies begin to represent the bulk of the HD content, the other 2 codecs gained importance.