Something I've already noticed, Sales don't start picking up until the last week of October, unless there is a big game, price cut, ect. If a console rolls into the xmas Q with nothing big happening, it takes until the last week of October to boost. As seen by 2008 for PS3 and 2009 for Xbox 360.
Wii in 2008 was still sought after, going by the fluctuations in September, in 2009 the September price cut automatically rose sales. 360 2008 had it's price cut in September also, and PS3 had slim and price cut in September as well.
So unless Wii does get a price cut or something else, don't expect it's sales to start lifting until the last week of October.