it's 6 dungeons, the first 3 will be reused with new puzzles and twists later on. Stacking up kinda 9 dungeons. And I think that the later 3 might have a second version too, but optional, part of a suppah side-quest or something like that.
And we can't go with regular dungeon counting for this game, since the overworld area that acompany each dungeon is like a dungeon itself. So it's more like 12 original "dungeons" in the game, and 6 reused "dungeons", but each of them smaller than a TP dungeon. So it's just different.
Will be almost all the time in a dungeon of sorts, but it will not feel as heavy as a TP dungeon, most of the time. First, because the dungeons are smaller in area (more like a central part with rooms and some paths around it, nothing like 7 floors). Second, we can exit from overworld sections back to the Sky and save in the middle of a dungeon.
Another thing that changed drastically in the formula, is that this game will have much less wander around (well, there will be some, but will be fast, practical, exciting etc. so you wont feel it drag), or at least it seems like it will be very segregated from the main game. I think that it's great, even Ocarina felt tiresome and dragged a bit at some parts in the field or when you get lost.
The result? I think it's a game that feels fresh and exciting all the time, but that can still be challenging.
My only concern is that they haven't showed us much of side-quests and mini-games, and havent given much emphasis on it. I'm sure that there is a lot of extra content(more than the usual, actually) but how it will blend into the game? One great thing about modern Zelda games is that, at a moment you are focused on the main quest and right after that, without even noticing, you are immersed in side-quests, challenges, mini-games, treasure hunting etc. And it just feels natural, like the world is alive and you are interacting with it they way you prefer.
So I'm afraid of SS being too straight forward, the main-quest too compelling and easy to follow so that the extra content will not blend into the game, and the regular flow will be just miss it... so that it plays out more like a Uncharted game, that you follow the plot viciously and before you notice the credits are rolling (just like in a movie), and not like a Zelda game that is a more organic experience.