Apple’s online store now lists the iPad Smart Case and iPad Smart Cover as discontinued for the iPad 2 and iPad (3rd/4th-Gen). The site now only shows a dark gray Smart Case and Cover, but both are unavailable for purchase online. Limited inventory may be available in some retail stores. This is a somewhat curious move, considering Apple has kept the iPad 2 in its lineup. However, Apple is still selling a number of third-party cases that…