Is it possible NoA is just waiting for an HD port on the Wii U?
Seriously, though, you aren't the first person to suggest this but I can't see where this idea is even coming from other than pure wishful thinking. While Xenoblade seems to be doing OK it's still hardly one of Nintendo's triple-A franchises that they would bother to remake for this sort of thing. Especially so soon after the original came out. What makes you think that such a project even exists?
It would sell Wii-Us. If you look at the minor graphical enhancement that Twilight Princess Wii got over the Gamecube version, it would follow that simply rendering the same models and stuff at HD resolutions would be an option.
If you imagine them redoing all of the games graphics to take full advantage of the Wii-U, then heck no, I don't see that happening.
It's part wishful thinking, and part "why the heck isn't this in North America?" There's just gotta be a reason.