I really think Nintendo would know better than that, however they might try and press their luck with the popularity of amiibos. Let's hope not.

If we got amiibo support in the game it'd be as level skins. After all, they've said bere that a Zelda skin isn't out of the realm of possibility

All other hardware developers shamelessly pray on people who are too dimwitted to realize when they are getting screwed over. Even if Nintendo were to go down the same path, you can't really blame them in the event that they are successful. The consumer would be at fault for creating the demand.

Still, Nintendo has commented on numerous occasions on how important it is to make sure that DLC is seen as extra content. Mario Kart 8 is an excellent example of this. With this in mind, as well as their reputation as a top-notch software developer, I highly doubt that they would be willing to compromise their legacy for the sake of short-term gain.

I wouldn't care since it doesn't effect me but I don't think they will go into locking away characters.

Maybe something like giving you extra blocks or currency if there is any.

Even if they do, i think it wont negatively effect thw core of the game. I mean, people who will buy this are the ones who really want to create their own stages and share it online, and play what others made.

Edit: + i see people complain how their amiibos are not compatible with a lot of Wii U games. 

No, but considering every major 1st party title (Smash Bros/Captain Toad/Rainbow Curse/Mario Party/Splatoon/Woolly World) has supported Amiibo since they launched, I would say it's very likely.

I don't see them locking away Luigi. Maybe Peach/Rosalina if they make it in. Maybe they'd lock certain music tracks to Amiibos?

Definitely a possibility, though I think it's somewhat unlikely going to happen.. will just have to wait and see, I guess.

Ugh, I guess it IS possible. Didn't even think about it until now. We haven't seen much of this type of behavior from Nintendo yet, so I have to believe that they wouldn't resort to these shenanigans.

I don't mind other types of unlockables, but the characters should never have to be purchased as DLC.