You know what totally should return but never will? The Magnetic Gloves. They're from Oracle of Seasons (and maybe Ages too, for all I know) and I just think they're the coolest item ever. I don't know what it is about them, but I find them extremely fun to play with. I'm not done with OoS yet, but there have already been some really cool puzzles with it. Can you imagine using something like that in a 3D setting? I would love to see it on a home console title!
Unfortunately, though, they're honestly really similar to a Hookshot, aside from the fact that thet can push you AWAY from things, too, and attract some magnetic items. I'm sure developers would rather use a tried-and-true item rather than my favorite little one-time-appearance one...
And rereading this thread made me think of so many other cool items that I'd love to see again. The Dominion Rod would be cool, too, and Roc's Cape would be awesome. But Pancake reminded me of the Lens of Truth, which is another one of my favorite Zelda items. I really, really would love to see that again (and I don't know why I didn't immediately think of it myself XD). I agree with Jade Fist that there are so many opportunities for hidden secrets and stuff with it. I feel like there's maybe a slightly chance THAT could come back, since it was in two games, one being the most famous of the series. Or at least something similar...