you will have to buy the limited edition Ganandorf amiibo to unlock the final boss battle

They will also feature a Zelda in wedding dress, which unlocks Links wedding to her.

Edit: Toon link will unlock their child appareance called Zink.

It depends on how NX uses Amiibos.

Any exclusives costumes, levels or game content in general will make me sick to be honest.

Let Zelda be complete 100% without need of day one DLC :p

Extra costumes is probably a safe bet.

By the time Zelda Wii U is released there will be no Zelda-related amiibos left in stock, just like how it happened for Xenoblade lol

It hopefully won't. Zelda is too good a franchise to needlessy tack on amiboo functuality

Maybe costumes or masks.
Or bonus rupees, hearts, arrows etc.
Or it works like a potion, making you stronger/more resistent for a small amount of time.

Basically, nothing really important which is fine. I can't see them locking anything major or anything in this game.

This.

According to experts, the delay is for the best. So, use the delay send by the gods to put all content into the game on day 1. No DLC, no amiibo, no patchs.

Weapons, cosmetics, extras, quests and maybe even something like Tingle Statues