I think that's a fantastic point. Perhaps Ganon acquires the Triforce and the Twilight Realm is the darkness spreading...hmm. Interesting theory.
The only problem I see is that Ganon would have to somehow lose the power of the Triforce between TP and WW. Regardless of whether or not Link dies...perhaps that explains the artwork (that I've yet to see, but have heard about) of Zelda holding a weapon. Perhaps we DO indeed play as Zelda...but only at the very end after Link dies? Perhaps SHE is responsible for defeating Ganon this time around...
But who the fuck is Midna?! Ahh! Can't Nintendo just release this game already!?