Look, another Sony fan, or graphic whore (for lack fo a better term) here to chime in how Wii will fade.
This is a debate crushed almost as many times as Goombas.
I'll put it plain and simple. The video game market you are familiar with was a small niche market that was stagnating. Nintendo is tapping the far larger casual market. Given the sheer size of it, there is easily a market base to sustain the growth for years to come.
You do realize by 2012 we'll have a new console from all 3 companies, don't you?
The rEVOLution is not being televised