What Nintendo needs to realize is that there's a reason they have such devoted fans. Because they always deliver such titles as this latest Zelda, Nintendo fans have good reason to stick with them. They should worry more about maintaining their tradition of quality titles, than about some gamers jumping ship.
Hmm, now for something completely different. For any system, there's a huge assortment of fan types. There are fanboys, hardcore gamers, casual gamers, newbies, and enthusiasts. Some gamers are considered to be immature and pathetic, for they bash other consoles and worry excessively about the welfare of their own. These kinds of gamers give the rest of the userbase a bad name. They are not fanboys. They are saboteurs.
The kinds of fanboys I appreciate, and the ones that Nintendo made a dedication to in Wind Waker, are true gamers. These kinds of gamers play games simply because they are entertaining, and they stick with Nintendo for they know that Nintendo will keep on impressing.
Fox, Nintendo is not in any danger of failing, nor does it need to be number one. The only benefit a Nintendo fan would get from having Nintendo be number one would be bragging rights.
However, even though PS2 is currently the market leader, do you see all the PS2 owners bragging? No. Does it really matter? Only if you're in it for the money.