Imagine Nintendo launches fall 2011 a new upgraded Wii with HD visuals and something else while Microsft and Sony will obviously keep their consoles for at least 2 more years because they are already powerfull enough and "future proof".
For you will this console be a "DSi" and considered a mature more expensive Wii, or a new gen console????
I can see this scenario happening and Nintendo selling in 2011 the current Wii at 150$ (supporting it till end of 2013) and the upgraded one at 250$.
PS - Nintendo totally screw up with our notions of generation, lol.