I'm not excited per se, but I am looking forward to them.
I already have Link and Marth pre ordered and am considering picking up Fox and Samus (as 4 of my favourites from Smash). I like what they've shown them to be able to do so far; is it perfect? No. But these are retroactive changes to established games. And I am keen to see what they do elsewhere:
Captain Toad, I'm confident will be costumes for him (picture him with Pikachu ears; bless)
Mario Party, I think will be much more robust (similar scale to Smash), perhaps an entire Amiibo mode
And I'm fairly confident that we'll see something akin to Infinity next year (perhaps Nintendoland 2). But with the Amiibo you are definitely buying the possibilities right now, and those possibilities intrigue me.
If they keep using them as costumes, weapon skins, etc. then I'll be happy to get that bit of extra us out of the models, but probably will be sticking to 2 or 3 of my favourite characters. As time goes on though, I think amiibos are going to be well integrated into games. Not in a physical DLC way, but in a 'heres a complete game, if you've an amiibo, here's some fun stuff' sort of way.
It could be a way of getting different level style in Mario Maker; scanning in Link gives you textures from Link's Adventure, Samus gives you Super Metroid textures. Non-essential but fun. Or themed weapons/costumes in Splatoon.







