The Video Game Critic

[QUOTE=The Video Game Critic]
Whatever they come up with will be considered a second-rate knock-off.
[/QUOTE]

And in Sony's case, that's already happened. Can you say Sixaxis?

If Sony or Microsoft did copy the Wii as an add-on it wouldn't work simply because the controller would not be the system's primary controller, and would simply fade away as a rarely used peripheral.