Is it really? It might be so in the rest of the world, but I can understand if they have some hesitation in Japan. We/They all thought Super Mario Galaxy would have stellar sales in Japan. Not even those commercials they had that made people see how similar SMG was to NSMB jump the sales for SMG.
Nintendo are idiots to even care if Japan likes this game or not.
Population of Japan: 127,590,000
Population of the USA: 307,698,000
Over twice the size and the North American market also includes Canada. And this will be big in Europe as well. Japan in comparison is a small piece of the puzzle. And Nintendo is already king of Japan with the DS anyway. NSMB Wii could sell ZERO copies in Japan and still be a big success. Japanese companies like Nintendo are morons for letting nationalism affect their business model, yet they get all disappointed when some game bombs in Japan but is a huge runaway hit in America. As long as you make the moolah why do you care?
Nintendo makes tons of money in Japan and they make tons of money in North America. What products are the cause of the success in each market doesn't really matter. This will be successful here and that means it will be successful.