Everyone should preorder not just one copy, but two copies. Preorder one from Gamestop and the other directly from Nintendo. This will boost sales and help get the game to where we want it to be.
Or not.
NoA only looks at the bottom line and will consider this game a failure unless it sells (despite releasing it a year late, in a limited run, with limited publicity, and after months of repeated denials caused many interested gamers to import). But you know what? Doubling the sales isn't going to be enough to make Xenoblade look like a success anyway. NoA only counts in the millions, and unless Xenoblade sells to that standard then it's a niche release that they don't want to be involved with.
Buy the game. Enjoy the game. Don't make the mistake of thinking that a double-dip here will say anything to NoA.
That said, it's still worth thinking about your preorder. Some people are talking about ordering from Nintendo directly because they don't like some of the business policies at GameStop, but if (and that's a big IF) the rumor mentioned earlier about GameStop pushing for the Xenoblade release has any truth then preordering from GameStop is a better idea if you want your dollars to count towards bringing over The Last Story or Pandora's Tower.