I think graphics may not make a good game but good play control and fun factor do. Wii is the next gen console, best graphics will always be outdated by new ones but innovative gaming experience is an ultimate one time deal.
Finally! Someone's realised that games aren't about the graphics, rather the gameplay. Case in point, Age of Empires. AoE2 was great in that it could be played for ages; it had tons of longer scenarios that resulted in a fair amount of gameplay. AoE3 on the other hand had great graphics, but only one scenario. And even that wasn't terribly difficult to beat, resulting in what, 2 days of challange?
I agree that graphics are good, but when game devs focus on them too much the game suffers. If Nintendo have made truly fun games to play I think it will take off