There is only one way to truely describe it: OMFG.
I only got about two hours into the game though, we have a strict rule of "No playing unless everyone is here to watch it." Which means about .. 2 hours a day between when Uath gets home from work and when Bow has to leave for work. At least we all get Thursday off.
I'm not going to spoil it for anyone, but I have to say, if you're "thinking about getting it for the gamecube" trust me, trust me, get it for the Wii. Don't buy a Gamecube, get a Wii if you can find one and get this game for it. Using the Wiimote for the sword is unbelievably fun. It really really does get you into the game.
And for you guys waiting to get a Wii after the hysterics are down, they're down. Nintendo isn't pulling a Sony, they've got enough for everyone to enjoy it. Our local stores have them, and they even had copies of Twilight Princess available on the shelf. (Though I don't suggest trying to shop this coming weeking, Black Friday and all.)