Since this is basically going to be the first Zelda game chronologically (released so far), I'd imagine Skyward Sword's story might explain how Link and Zelda are so planted in fate with eachother; which will probably have something to do with the triforce. Although, if the triforce will play a role in the story, who gets the triforce of power? Ghirahim would be the obvious pick, but now I'm getting too deep into unknown territory to contemplate further. :P
... I need to get my Wii fixed ASAP. .-.