Those plasma screens are 16:9 and have non-rectangular pixels. Since all high-definition content is also 16:9, if you play it back on a 1024x768 4:3 display like the iPad Mini you're actually watching it in 576p with black bars at the top and bottom which is unquestionably standard-definition. In Europe and much of the rest of the world DVDs have always been 576p and there's really no way to dispute that those are standard definition.