I, for one, am a believer in every Zelda having a unique Overworld style. Ocarina of Time showed us what a normal, boring pixel Overworld would look like and gave it more dimension. Windwaker had taken a daring step, allowing for a massive world map and centralized dungeon experiences combined with hub areas as a trade off for cartoonish graphics. Even Phantom Hourglass had a unique traveling concept that dealt with a good deal of space alongside combat and treasure hunting. Twilight Princess was almost a letdown in that sense, showing us massive amounts of countryside with not much in it and disjointedness. They attempted to show a full Hyrule but just didn't have enough power in hardware to show it- and it ended up feeling more like Ocarina of Time's Overworld. Also, since the space was so big there was almost no way you would want to travel it by foot- there was no urge to get off and explore as a human or wolf- it wasn't worth it (even though there were plenty of treasures to be found. I have wondered how exactly Nintendo would keep the concept of an Overworld relevant in a day and age of linearity or over-spaciousness?
Allow me to elaborate for a moment- Many games that are shooters or action games have very linear routes and gameplay- whereas adventure, role-playing, and sandbox games (obviously) have extremely spacious maps- mostly to immerse the player but partially to show off their processing power. How could Nintendo, the company with neither graphical nor processing power, hope to match this kind of competition? By redefining it's staple games- Metroid used room-upon-room with puzzle upon puzzle in 3D to achieve the feeling of travel. Mario opened its gates to the heaven, testing our mind with conceptual as well as pure platforming puzzles. Zelda, however... could either fall back on simple graphics to make a huge game or revolutionize the Overworld's design completely. Which they did... by going right back to form.
Syward Sword has three main areas to its map, which can be accessed by the secondary Overworld function. These three areas may or many not have three dungeons in them, each. In which case, one would think they would have to spend a good time in each area at a time or pointlessly be forced to use the secondary Overworld to travel often. But that is not what Nintendo had in mind when creating these main areas. They mentioned the Overworld having more dungeon elements in it- though that seemed interesting, we immediately assumed that was in close proximity of the dungeon. However, the very first video of the game revealed the truth- that this Overworld WAS a dungeon.
Since the first days of Zelda, each new "square" of map has been a new challenge- designed a certain way and littered with a certain amount of enemies or secrets. The dungeons were often the more centralized, concentrated versions of these challenges, thus becoming noticeable in their own right. There was always dungeon-oriented gameplay, even in the Overworld. Nintendo has taken that idea and simply enhanced its graphics, the dimensional level, and motion controls to give a new, revolutionized Overworld. However, in the first few Zelda titles, items were required to expand the boundaries of the Overworld itself- in addition to extra hearts, of course. How should 3D Zelda be any different? That is why the Overworld now integrates more dungeon elements than ever- however, unlike Metroid Prime's method of rooms connected by doors and cut off from one another by massive walls, Skyward Sword's Overworld has levels where you can look down on your Overworld/dungeon, see where you need to go to get closer to your next goal. This is an Overworld that is not merely sprawling- it has strategic travel.
Honestly, that's not something you get often in video games- though it's honestly as old school as you can get. The inclusion of motion controls means that every battle you have in the Overworld will seem like a deeper, more intense fight- think the new Prince of Persia but more based on motion control. Enemies are more of a challenge in general and therefore require effort and time- and that's what it all comes down to. (More on that later.)
These elements are those that excite me the most about the impending release of Skyward Sword.