If they add one or two of those dungeons that were left out of the first game, I'm in; otherwise, though I love me some Wind Waker, I'll have to pass on it.
I could see the difference in the between the video and the original Gamecube game, but, as others have stated, the reason the contrast isn't so great is that Wind Waker's original art choices stand out and make the game age well. The art style is still great on the Wii U, but it isn't the right choice for showcasing HD.
Still, if it gives more people the chance to play this great game, then I'm for it. I'm just not sure it would be for me at this point, since I can easily play the old version.
I may have missed it, but have the developers stated anything about the control scheme? Are they mapping it to motion controls or will they keep the control scheme in the traditional style? I would hope it's the latter.