Problem is : Nintendo DO own third parties. Basically, despite numerous third party titles being released on the Wii, almost only Nintendo titles are reaching top of the charts. The 3 million sellers of the Wii are Wii Sports, Zelda and Wiiplay.
And if you read any forum, you know the most anticipated titles are : Smash Bro, Mario Striker, Mario Paper or Metroid.
How long will third party studios deal with this situation ?