The Legend of Zelda: Breath of the Wild - items can be upgraded, weapon slots increased

Coming from a Kotaku interview with Eiji Aonuma...

“There’s a lot of things you can collect in this game, whether it’s food, clothes, weapons. So in past Zelda titles we put all of that under the umbrella of ‘item.’ We separated that out in this one. And in terms of items that are necessary to solve puzzles, that you kind of get early in the game. And then you can actually later upgrade those. Even the number of weapon slots is limited in the beginning. Doing something later in the game will increase that and let you collect more weapons.”