The reason I said late 2011 as a release date is because Natal and Arc may force Nintendo to speed up their time-table.
Nintendo is already running on fumes with their 3rd party developers... the casual market is what is sustaining Nintendo right now. I don't know how much of an impact Natal and Arc will have on Nintendo sales, but Nintendo definitely has to be concerned.
The Wii already feels dated, and it is being passed over for all the big multi-platform games.
I think one of the big determining factors will be how good Nintendo sales are through 2010, especially the holiday season.
If sales don't grow or remain flat, then expect to see the new Wii earlier than later.
Most anticipated games of 2011:
Uncharted 3,Legend of Zelda: Skyward Sword, Rocksmith
Modern Warfare 3, Super Mario 3D
