No, no, no, no, and once more for emphasis, NOOOOOOOOOOOOOOO.
I can't stress it enough. The central dungeon was one of the worst ideas they have ever had for a Zelda game. I never liked going dungeon, Spirit Tower, dungeon, Spirit Tower, dungeon, Spirit Tower. It may be a variety of puzzles or whatever in the central dungeon, but I still don't like going back to the same place over and over again. The Temple of the Ocean King was just bad, and the Spirit Tower wasn't much better. If there is a central dungeon in Skyward Sword, and it isn't at least 5x better than the Spirit Tower, I will destroy the game. I won't play it, ever. The central dungeon is absolutely horrible and I don't want to see it in any more Zelda games. It doesn't bug me as much as the horrible train and boat travel in Spirit Tracks and Phantom Hourglass, but almost as bad. It has a bit of potential to be good, but let's hope if they put one in that it IS good.