IMO, you're close but not all the way there.   The change in controls allowed Nintendo to have the Wii do things that couldn't be done with the traditional controllers.

There are 2 important things about the controls that have changed.  One - They have been simplified.  Less buttons to have to deal with to play a game.  Two - The controller itself has been made fun.  Having to press one button at various times would have been boring.  But to swing it about, or to stand on it, or to turn a wheel about, that's fun.

The other change is how the console is marketed.  How much marketing effort was there for GC to expand the console's gamer population.  The Wii alpha mom party equivalent?  The Miis?  The non-traditional gaming press coverage (retirement homes?  rehab?)

Will new peripherals be created for the Wii?  You know that the Star Wars light saber will be a popular one.  But new ones "needed" or else the Wii won't sell?  First, there needs to be a lot more games created for the current peripherals before that happens.

But see, this is where you are wrong. The Wiimote -the system's standard controller, and not a peripheral- is what makes all of the new things Nintendo is doing possible. The only game 'tied with a peripheral' is Wii Fit; everything else can be played with nothing but what comes with the system.

I quoted myself to make a point.  Not because my argument here was right, it may or may not be, but because both sides of this argument in this thread are clearly wrong.  No one thing = success.

You guys can keep ignoring reason all you want, but success requires looking beyond your preconceived notions and look at things impartially and rationally (even crazy radio hosts look rationally at the requirements of their profession, voice, tone, entertainment, pandering...).  Nintendo looked at itself and the gaming industry from an outside perspective to see the flaws in the previous profit model.  They needed to cut on development cost and focus on marketing to new users through ads, games, hardware, and asthetics.

And in other news the pope is catholic and China is a part of Asia.