The Super Mario line of Amiibo continues to be excellent.
Jr. and Toadette HAVE to be ones they have planned for, just wonder who else would join them in a phase 3?
I think Shy Guy is a strong possibility, he's right up there with Boo as one of the most beloved baddie characters.(I'd buy Shy in a heartbeat)
Dry Bones and Birdo seem likely choices too. Nintendo have neglected them in recent years, yes, but they do have a lot of fans.
Of course, I could also see them dedicate an entire phase to the Koopalings... ;D