Honestly, I think everyone here's making too much of a deal out of this on either way. A simultaneous release would not blunt sales or excitement for the NX, and a staggered release wouldn't hurt Nintendo in the long run.
The only way a staggered release would help Nintendo is if some Wii U owners who weren't going to buy a NX at launch were willing to buy one just to play Zelda a few weeks early. Wii U doesn't have that big of an install base, and of that install base, I doubt there's a significant portion that wasn't going to buy a NX but would be convinced to do so by a slightly sooner release date of a single game.
Meanwhile, as several people have mentioned before, Nintendo has already done staggered releases on multi console releases. Twilight Princess was a couple weeks, and Smash was out for a month or so on 3DS before it released on Wii U. Neither of those caused an uproar by Nintendo fans, so I seriously doubt this will.
Either way, it'll have a minimal effect, if it has any at all.
