Sure, there is a need to burn HD to discs.
I just figured from the op, that he wants to play content like Planet Earth he has as an HD file. Imo for these kind of files it might be easier to stream or directly connect the pc to the HDTV. (Streaming would probably be the easiest way). Afaik in order to create a DVD with HD content you have to jump through quite a few loops, including software that is not inexpensive.
However if he really wants to create
HDDVDs (
) then the guide you've posted should get him started.
