I like Majora's Mask world. It wasn't exactly huge, but it was nice. There were little mini games and quests everywhere. Stuff like an invisible man, the guy in the tree, the bird who stole your stuff, the dancing guy, etc. Made it feel full of life. If they want to do a large scale world like that, then I'm completely in support of it.
Actually the talk of finding actual items in the open world sounds great. Like how Link Between Worlds worked except instead of buying/renting them, you did puzzles in the overworld to unlock them. Spend tons of rupees upgrading those items so you can get past other puzzles or something to that affect. That might be pure genius if they did something to that affect.
Hell, bring masks with affects back. Quests in the overworld involving that might be fun.
They have potential to do a lot of nice things to make the overworld full of life, I just think they won't do it, but we will see.