Briefly, to have your video encoded in HD, all you have to do is upload the video in 720p format. Note that the usual file size (1GB) and duration limits (10 minutes) apply. You can upload in a variety of formats; I used H.264. YouTube first creates a very ugly 320x180 video for normal viewing, then the big enchilada.
Here's the uploaded video the guy made:
(click on the "Watch in HD" to watch it in 720p)
Comment