It really will be interesting to see how much demand levels off once people realize that it doesn't run Windows - i.e. (as others have noted), it is not a desktop PC (as most people understand that word/phrase).
Keep in mind that most people who use computers don't even know that it runs Windows (I.e., the concept of an operating system). They just know that when they turn it on, they get Word & Excel. So, they don't even have the mental model to realize that a computer that doesn't run Windows - is somehow a problem.
And some folks need to stop being fanboys and see the forest behind the trees.
(One of the best lines I've seen on this board lately)