Nintendo is not going to die anytime soon, but I can imagine that if they do, ny interest in gaming would seriously drop off. I don't buy the whole "if you're a real gaming you would still play the others" argument. There's still such a thing as taste and opinion that factor in this issue. I'm sorry, but overall I don't care for what the competitors are selling right now. There a few nice a exclusives, but these machine play second fiddle to my cube right now. I love adventure and platformers, which I feel the other console are difficient in. There are too many PC type of titles that are coming to the Xbox for my taste, while the PS has too much of "teh cool" games that may or may not have the gameplay to go along with them. Plus, I dread what the next generation will bring with all this complicated set top box, internet functionality crap the other console makers will be bringing. I just want a simple game machine, and I will look elsewhere because of that opinion. Even if that means I have to stick to the Gameboy, I think I will be a lot more happy about that than dealing with some of the possiblities these machines bring like pay for play for instance.
I don't jest when I say my interest will wane significantly. I stopped for good awhile after the Dreamcast was killed and in the end videogames are a hobby not a neccesity. I won't melt away because I can't play Mario, and I don't think anyone can call me a fool or an elitist snob if I truly feel that after Nintendo there's not much left for me play.