I think it'll be more likely to run at 1080p than 60fps.

Zelda has never really been a game that relies on fast reflexes and accurate feedback (unlike Smash or Bayonetta), so I think Nintendo would rather lock it at 30fps and shoot for making a visually more impressive title. Especially considering how important Zelda is to the 'mature' audience who like to count their peas (presumably to make sure they're getting the same amount as their little sister)

Wouldn't surprise me, I've heard that a lot of PC ports of console games normally run at a set 30fps no matter how powerful your machine is because of that same reason. It could also be because having double the frames affected gameplay on a negative way, example; hackers made Kingdom Hearts 2 run at 60fps on an emulator, though that caused the "gravity" in the game to be "stronger", AKA you fell to the ground at twice the speed you normally should, maybe something similar would happen with Wind Waker? I dunno.

I think people are overestimating open world. It's just a large area that is capped by whatever the highest view distance is. So pretty much like HyWa already is. There isn't a lot of geometry in a Zelda game and it won't be hugely populated. Add to that low res textures and it's a fairly forgiving game.

I will actually have a big laugh if they can't manage to bring it to 720p60.

Except HW never lets you see huge expansive areas at once, blocking the way with walls and other obstructions, while we've already seen Zelda U stretch for vast distances. ZU is also lightyears ahead of HW in graphical fidelity.

There isn't a lot of geometry? Though geometry itself isn't that limiting anymore, unlike shader effects alltogether, it depends on a lot of things. Will Zelda have actual physics? how much AI is in there? How much does it load on one time? There's actually still a ton of things that can make open world games much CPU heavier. So there's that limiting factor.
And there also is the GPU. Looking at what we've seen there will be some fx more or less absent. Others seem really good.

I honestly don't know.

I'm pretty sure HyWa doesn't run at 60fps. That, or it dips a LOT.

It has nothing to do with reflexes. 60fps just feels better. 30fps feels like playing in peanut butter an watching a slide show.

Well... 60 fps would mean less things on screen and I don't mean in terms of draw distance... There would be less trees in forests, less animals everywhere, less monsters roaming around, less houses in towns, less people in towns, as well as plenty of other things if they want it to be a consistant frame rate experience which Nintendo is known for. Its not just about the size of the world, its about the number of things that can be seen at any given time and with 60fps, there will be a lot less things due to the performance limitations of the wiiU. Games like Mario Kart 8 and Smash Bros are great with 60fps but those games aren't open world which Zelda is and due to the wiiU's limitation, there will have to be sacrifices

And the world will be giant since like one potion of the map was like the size of twilight princess and theres like 6 or 7 portions more that are equally as big if not bigger and I am pretty sure it will be seamless

When i say "no problem" i mean in regards to it being a possible transition. There are various factors to consider, but for a console like the WiiU (that's mostly GPU reliant), 720p/60fps would in many respects be easier to pull off than 1080p/30fps (which has a pixel count of about 12.5% more). It wouldn't be as simple as the press of a button, various parts of the game itself would need to be reworked slightly (such as animations), but if you have the resources for one you should be able to do the other.

Answer to your second reply:

I'm not an expert, but the topic interests me

Anyway, something being "bigger" doesn't mean it's more difficult to run. All that really matters (most of the time) is the LOD, and how far a game maintains that quality. You'd be amazed how awful some of the assets open world games use for things far away from the player :p The PS2 would look away in disgust at some of them.

Cel-shading isn't necessarily easier to run, but it does often let you get away with having worse overall assets, which is likely why Nintendo chose it. The lower the quality of the local assets they can get away with, the larger they can make the LOD fields, which in term makes them less noticeable (something most open world games do their best to accomplish).