I voted HD DVD why you say? Well older people know what an DVD is, if they own a HD tv then they know what HD stands for, combine the two and you have an instantly recognizable name.

Blue Ray, hmm, they have no idea. Unless you knew what it was before you entered the store good luck.

HD DVD i think will win for this very very simple fact. The majority of users are not informed hence why Spiegel had to include links to both. People understand what HD DVD is and blue ray is just to ambiguous.