During today's Nintendo Direct, Wave 5 Super Smash Brothers Amiibo were announced, along with Splatoon Amiibo, original 3DS support, and more interestingly, card Amiibo and wool Amiibo.
Since Adam Dork has already written about Splatoon's amiibo functionaliy on the site, I won't be talking about it in this article.
At the beginning of the Nintendo Direct, Satoru Iwata revealed that the fourth wave of Super Smash Brothers Amiibo on May 29, which will include Robin, Lucina, Charizard, Wario, Pac-Man, and GameStop exclusive Ness. *UPDATE: *It was later confirmed a Jigglypuff amiibo was coming with Wave 4, and is Target exclusive.
After this, Iwata also revealed waves 5 and 6 of Smash amiibo. Wave 5 will have only Dark Pit and Palutena and be released in July, while Wave 6 will have Bowser Jr., Olimar, Dr. Mario, Zero Suit Samus, and Ganondorf, which will be released in September.
Later in the direct during a demonstration of Yoshi's Wooly World, Nintendo revealed that the game will receive Amiibo with a twist: the amiibo will be made with yarn to be consistent with the game's style. The amiibo are used to make a clone of Yoshi that follows the player's exact controls. (The amiibos are featured as this article's header image)
Finally, Nintendo revealed they will be going ahead with their previously talked about plans for card amiibo, to begin with a interior design focused Animal Crossing spinoff with the 3DS called Animal Crossing: Happy Home Designer. Along with this, Nintendo confirmed they will be releasing an an adapter for Amiibo for 3DS, which until this point has been exclusive to the New 3DS models.
If you want more info on today's Nintendo Direct, be sure to check out Adam's article on Splatoon, and my article on the indie games shown during today's direct.