Update: Nintendo of America has sent GamesRadar a new statement clarifying the unavailability of some amiibo, as well as giving a small sliver of hope to those searching for a Marth to call their own. Here's the official word from NoA:
"Some amiibo were very popular at launch, and it is possible that some amiibo in the United States, Canada and Latin America may not be available right now due to high demand and our efforts to manage shelf space during the launch period. Certain sold-out amiibo may return to these markets at a later stage. We are continually aiming to always have a regular supply of amiibo in the marketplace and there are many waves of amiibo to come."
If nothing else, the statement makes it clear that the official plural of amiibo is "amiibo."
Original story: If you've had your eye on a certain amiibo figurine but haven't picked it up yet, take heed: Nintendo says it's not likely to send more shipments of less-popular characters. Once the initial run that hit shelves alongside Super Smash Bros. for Wii U is exhausted, that could be it.
Granted, if you've been drafting up a pros/cons list for a Mario or Link figurine you're probably safe - the company said it plans to keep its 'more popular' characters in stock for the foreseeable future. But if you'd like to grow your own Villager, Wii Fit Trainer, or Marth (hey, he's popular with Fire Emblem fans/competitive smashers!) NPC rival, you may not find them in retail for too much longer.
According to a Nintendo statement given to GameSpot, these limited production runs for certain characters will help free up shelf space for the expanding amiibo roster, while keeping the classics readily available. It's a fair point... I just wish I knew that a month ago when the supply of Villagers seemed endless so I just got a Samus instead.