What's most impressive (and I think people overlook this) about the Wii is not the fact that it's successful. It's the fact that if it wasn't successful (even if it was only slightly so), then Nintendo would have found itself in a very bad position. That's what so great about the Wii (or well, Nintendo actually), that they were willing to take a risk. I think that might also be why the Wii is not all that powerful, and the fact that it actually makes profit for Nintendo. If it fails, at least they still make a small profit. Course, now they're just madly making money from it. I read somewhere on here that if the Wii was $200, it would still make a profit for Nintendo of about $20 (course... I assume the guy who posted this converted the numbers to American dollars and did it right and all). So that means the Wii makes for Nintendo around $70 per console. If we assume that's the case WW, then at 6 million units... Nintendo just made 420 million dollars. I wish I were that lucky.
But all in all, they were lucky that it worked out. If it didn't, then I guess a new console would have come out a lot quicker than a Wii2 would.
We could also ask if the Wii did have better graphics and better everything, and cost even $400, would it still be doing as well as it is now? I can't honestly say. I think it would still be a player in the market, and the three consoles would probably end up being closer in WW sales during the next few years. As it is, the Wii is just an affordable console, and also is liked by more than the normal gamers... My father for instance. So as it is, those who don't need the great graphics for their games don't mind paying for it, because it's so cheap. Remove that, and you probably remove some of the Wii's sales.