Do you want to buy one because you're excited about the games or do you want to buy just because they're so much in demand and hard that holding a Wii in your hands is all the reasons you need for buying one.
I think a surprisingly large number of people succumb to the Wii hype. Case in point: me. I'm not a Nintendo fan, have never played a Mario/Zelda game in my life and really love my 360. I was only mildly curious about the Wii remote control but couldn't care less about 98% of all Wii games. The Wii had been sold out in the Netherlands for at least six months, so when I saw a stack of Wii consoles in my local Mediamartk store, the hype got me. If stores would have been overflowing with Wii stock, I'd have probably shrugged and only get the Wii if I really, really wanted one. But since Wii's were so rare, I suddenly had to decide if I wanted to satisfy my curiosity right now because that stack of Wiis would be gone in a few days. My rational mind turned itself off at that moment and consumerism/hype took over.
And so I found myself with a Wii in my hands plus two games (Zelda and RE4) even though I'm not really a Wii gamer, dislike the lores graphics, the childish interface and lack of online features. I do like a couple of Wii games but I generally think the Wii is overrated and in a different league compared to my favorites, the PS3 and 360. I don't think Nintendo will care, because I'll still have contributed to Nintendo's world domination even though I want the other two consoles to win the race.