I guess a lot of it speaks to the basic hardware disparity; obviously on Gamecube you had to make the sea mostly empty because it's like a loading screen for the next island, while on a system with 25 times as much RAM, you can fill your world with more stuff.

Well good thing Hyrule Field has more detail than the Sea, and most people loved Wind Waker.

Take this with a grain of salt as I haven't played WW since it originally released.

How about this lets look at 3 points: point A is where you are, point B lies almost directly between A and C. Point C is where you are going.  In WW lats say that point C is an island.  Because the ocean is flat (or 2d) you will be able to see everything static between points A and C. While you are traveling between points A and C there is no point in turning around, you won't see anything static that was previously hidden because you are on essentially a 2D plain. Now lets do the same thing with ZU . You are at point A and are traveling to C what you can't tell at first is there is a valley containing a town at point B.  You can't tell this because with elevation you now have three axises to deal with.  Something can be hidden in a valley, or the far side of the hill.  If you have one of those two things you now have to turn around to see the backside of the hill, something you don't have to do in WW.  This changes the gameplay, and in my opinion adds to exploration.

But a maze is comprised of corridors. I don't even know what you're trying to say with that comment.

And either way the point still stands, terrain difference is minimal in that getting to your point of interest is still going be relied on by some kind of vehicle. Just because you're running on horse back to your POI vs sailing, isn't going to make the experience any more or less fun. Do you not get that running around to your POI isn't going to make the experience any more fun? The island is still going to be that distance away no matter what.

I think you may be oversimplifying and missing Curl's point.  I would also say the OP is oversiplifying to be able draw a dirrect comparison when they are similar and not the same given 2D travel vs. 3D travel

Of course it adds to exploration in that way, but that's not what's being argued. It very inconsequencially changes the way you go about doing the same thing. That's not extra content. You're not exploring more things, you're just exploring more of nothing. If there were a giant wave, an example I've already used, in the ocean of WW, you wouldn't be able to see what's past it. Maybe you want to and maybe you do. It doesn't change the fact that you did the exact same sailing for the exact same distance to get there. It just changes the way it looked to get there. That's not a signifigant change in gameplay at all. That third plain didn't add anything tangable to getting from point A to point B. You know what is tangable? Shooting swimming enemies, filling a map piece, scavenging for sunken treasure, exploring the remnants of an abandoned island. Riding over a hill on a horse or through a bridge or a bunch of trees instead of your usual grassy plain does absolutely none of that.

Perhaps I worded that poorly. Its not a corridor, it is just vast, empty and boring. Much like a corridor, it acted as a way to take you between the different rooms, the places that were actually important.

Infinite directions to more emptiness... That's not positive. There wasn't a "ton to do in the ocean", far from it.

I love WW. I can accept a large empty ocean. I set out very early to get every single map square and visit all the islands. I finished (almost..) all of the figurines.

Does not excuse the ocean for being empty, flat and boring. It worked though, it served its purpose. But it is what it is.

Satisfied? They took it as far as they could. They accomplished a lot, nothing wrong with that. But they wanted so much more.
*enter Zelda WiiU*
I have great hopes for this game, and I'm prepearing myself to get blown off my feet. From what they've said and what they've shown, I find no reason to believe Zelda WiiU will become a WW on land.

There was a ton to do on water. It was far more than just a way to get from one island to another.

Bolded - that is an assumption we can't make about the new game since we haven't played it.  You claim there is not extra content without even knowing what content there is.  You could be correct or you could be flat wrong. Again we won't know until we play it.

As for the wave you mentioned we know there wasn't one but let's say there is.  The wave would be our point B, we weren't planning on stopping at point B, we were on our way to point C until we realized that there was something obscured at point B.  You said "Maybe you want to and maybe you do. It doesn't change the fact that you did the exact same sailing for the exact same distance to get there." you're correct you did the exact same sailing to get to point B, only you were going to point C, so it changes the trip from points A to C when you stop to investigate point B.  To say it doesn't change the trip is only valid if you ignore point B and go straight on to C.

"Riding over a hill on a horse or through a bridge or a bunch of trees instead of your usual grassy plain does absolutely none of that."

again you are assuming there is nothing on the other side of the hill, from the game play video we know that is an erroneous assumption as we watched them round a rock and come upon enemies.  We watched them round a rock and come across a group of horses.   We have played WW and we know there were no large waves obscuring our view to the horizon.  With three plains it very much makes a difference the route you take, with two plains you can see to the horizon and nothing is hidden. Unlike with two plains if your north south course is 4 meters to the west or 4 meters to the east that could make a difference as to wether or not you see the enterace to a dungeon.

KORL and Epona can both, it seem, be left to sail/run in the direction you pointed them in, in WW there was little to run into, in ZU there seem to be lots of things to run into.  We will have to wait and see if the AI for Epona does the job well or not.

The bolded wasn't directed at the game as a whole. It was directed at your hill theory. It doesn't matter if there is something at both points B and C. It doesn't matter if you ignored point B. That doesn't mean there is more content in one than there is in the other. It means that you chose not to investigate one point and not the other. I'm not assuming anything. Your example does not prove your point. Hills don't add any content. Trees don't add any content. "Rounding a rock" that obscures horses doesn't add content to the world. It literally just means that you have to round a rock. That rock didn't make the world less empty, it just made the world 1% more rock looking. Hills just make the world more hill looking. Trees make it more tree looking.

If there were suddenly a thousand trees and a thousand rocks and a thousand little water hills in the oceans of Wind Waker, it would have successfully added a whopping 0% of tangable content to the game. It's nothing but aesthetic dressing. That's great for atmosphere, but that's exactly what people mean when they say that Skyrims world is empty. Plenty of hills, trees, cliffs, "rocks," lakes, and whatever other insignificant aesthetic things you can think of to make the game look nice, but very little tangable and worthwhile content to do in it. Riding a horse around a rock doesn't constitute something to do.

 I can agree to most of your last statement.  Hills and trees don't ADD content but my point was that they can MASK content making you explore between points A and C rather than just waiting for something significant to appear on the horizon as you sail along.  To me that adds to the travel element of the game. It makes it more engaging to me as a player when I actually have to explore rather than just watch the horizon.  That's part of what I was talking about having to turn around, you didn't have to turn around in WW more than one or two times per section once you got to an island, all the travel in between was just sailing in a direction.  I'm not trying to attack WW either, it was a great game.