It has been heavily speculated that The Legend of Zelda: A Link Between Worlds was going to feature non-linear gameplay after a certain point, meaning that players could choose which dungeon they wanted to experience first. But after today's Nintendo Direct we finally know how Nintendo planned on designing these dungeons. After all, the usual Zelda formula requires a new item that is used to solve puzzles in subsequent dungeons.
During the Nintendo Direct, Satoru Iwata explained that Link can find all the items he could want available for rent at Ravio’s Shop. Once a player has completed the relevant dungeon, they may then permanently purchase the corresponding item from Ravio. A hint was dropped when Eiji Aonuma posted an image on Miiverse revealing a shop owned by a suspicious character, and it turns out that this character’s name is Ravio. Moreover, Iwata clarified that Ravio is not related to Nabbit, who features in New Super Mario Bros. U and New Super Luigi U.
Source: Nintendo Direct