I will say this: the worst case scenario in which no one buys a single wii u (which is not the case cause they sold 1 million worldwide by today, not including 3ds which selling like crazy!) the price will reflect the amount of cash they have which is 15 billion dollars, meaning 13 dollars a share. that's why the smart thing to do is to buy at this price from the fools that sell now.
I don't think it's possible for a stock not to drop below a certain price point other then zero. Nintendo still has hardware/manufacturing costs, they have to pay their employees, their investors who decide to sell their shares, and other expenses. If this stock can't drop below $13, you'd think every investor out there would be jumping on it since there would be nowhere to go but up, but that's not possible. I noticed someone who read this thread posted about this on reddit, which you can go read under the "investing" sub. I'd post the direct link here but I don't think it's allowed since I just tried and had my post removed it seems.