Dodece - surely that's the main differentiator between the Wii and the PS3/360?
They are the machines with the improved graphics engines (same games and gameplay) while Wii is the leap from joystick control to motion sensing (new games - new ways to play)
Single screen
I think you're right that the 64 was revolutionary but I also think the Wii is revolutionary - the difference is the catalytic factor isn't the processing speed and what it allowed Nintendo to do, but the input device. Maybe more akin to the mouse or the joystick.