Square Enix is preparing a title called Bravely Default: Flying Fairy for the 3DS. It is an RPG title out of Japan that looks interesting and makes use of the AR functionality of the 3DS.
I have not seen much on this title yet, but it stands to reason that the title plays like a classic RPG. Here are a handful of new screenshots - I have to say the visual style is appealing.
And a quick peek at what the AR card may look like: