The Official Nintendo Magazine UK have announced that starting August 23, 2012, a pack of 3 Kingdom Heart 3D [Dream Drop Distance] AR cards will be available from Club Nintendo, for a cost of 200 Stars. These are different to the 2 cards that came with the European version of the game. Cool! Thanks to Beta from KH13 for the tip.

Update (August 25, 2012): Nintendo UK have uploaded a picture of the AR card set, and this can be seen below. This picture shows that the AR cards are the remaining 3 cards that Japan and North America received, but Europe didn't-- meaning that, now, all 5 cards have been released in most regions.

Update 2: They have not been added to Club Nintendo Australia. We are hopeful this will change in the near future.