It is worth it, the camerawork is amazing, especially the aerial shots. I am gonna use VLC player to take some snapshots so I can use some of the scenes as desktop or screensaver pictures.
I have only watched part one so far, but I'm gonna log off and watch part 2 in a little while.
Guess I'm stuck in the old ages. I enjoy 480p for movie watching, 92" screen helps, and really only watch nature shows in HD on the TV.
I think HD is too detailed when viewing people and adds little to the over all effect. I don't really need to see nose hairs, pimples, etc... For wildlife, underwater scenes, it's amazing.
I absolutely love Planet Earth. Blue Planet too. I'm waiting for a holiday to get them on dvd, since it's too expensive to be a practical everyday purchase.