http://youtu.be/C6uHEkdTkac
Here's a quick summary of the video:
1.He got his Lucario amiibo from Nintendo World (I think), and met a nintendo rep
2. The rep told him that they will get
a ton of Rosalinas
3. The next rare (or rarer) amiibo would be
Shulk
4. At the end, he said the rep told him
NONE of the amiibos is discontinued! That including Marth, Villager, and Wii Fit Trainer. Nintendo is still making them.