Was at the store last night, and got AppleCare+ for my Sport. The girl was totally surprised, seemed like this was the first watch she seen in the wild. Furthermore, they checked no functionality (like they do for the iPhone when you come in a purchase AppleCare+ after you already got the phone) - simply read the serial from the back swiped my card, done. Also she was amused when the email notification for the receipt lit up right away 