This is actually good news for Xenoblade since it gives it a better chance of selling in the West now. Having 2 massive open world games coming out around the same time was always going to make one take attention away from the other, which we all know Zelda would get all the hype. Now Xenoblade will be the only game of its kind coming out on the Wii U this Fall, which will help give it more attention from people who before would have ignored it in favor of Zelda because "OMG IT"S ZELDA".
Yeah, only on a Nintendo console is that a problem, having competition is a good thing, having variety and choices is a good thing, but not if you are talking Nintendo they can't compete so they make their games and consoles fit into their little world and spread out their releases because Nintendo fans for some reason can't buy more than one game at a time? Last time I checked the big boys get one of these types of games every couple of months, they seem to be doing pretty well. Also Zelda is going to sell to an entirely different segment of the market than Xenoblade X, there is some overlap but X is an RPG Zelda is not they are different demographics. RPG gamers are starved for something to play on Wii U, Zelda gamers have plenty to hold them over, especially once you dive into VC.