Club Nintendo North America has brought the case back by popular demand. The case is made out of plastic and carries 18 Nintendo DS or 3DS games, It also includes 4 double sided covers. I managed to snatch one up when they first came out and made a unboxing video that you can see below. The case will set you back 250 Coins.
Mark of Mastery Collectors edition will include a copy of Kingdom Hearts 3D, a branded clear hard case skin cover, 12 art cards, and 5 AR cards that can unlock rare Dream Eaters such as Meowjesty, Frootz Cat and Kab Kannon. All of this will come included in a sealed magnetic box. The box will be available for $54.99 the game launches on 07/31/2012.
There was an update made available sometime yesterday. The update could have been in preparation for the Mario Kart 7 update, seeing as how it didn't do too much. The only reports I'm finding is that the update did stop most flash carts from working with the 3DS. To get the Mario Kart 7 update head on over the eShop. Mario Kart 7 will NOT let you access the online multiplayer option until you do update.