Video games seem to be recession proof, and Nintendo is the only company who can bring in revenue from video games by selling non-third party titles.
Not only that, but the titles they sell themselves are the most popular on the console, and the driving force behind their profits.
You are selling at a time when the Wii Fit hype is about to take off. As soon as the media gets wind of the shortage, every morning show across America is going to be talking about the Wii Fit as the next revolution, even if it isn't true.
Mass hysteria is going to lead to another shot in the Nintendo arm. Wii Fit might be the best selling title this year, and it is completely proprietary to Nintendo. All the profits go to them.