Fad isn't over it's just a supply issue.
But if the financial crisis gets worse and we enter a deep recession Nintendo is going to wish they had shipped a lot more Wii these previous years, even if it had meant reducing production later in the Wii cycle....
Wii is probably going to suffer a little these preholydays months too as aside from Wii Music the Wii catalog in the coming months isn't really better and beyond the HD consoles catalog ( there's never been as many decent HD titles coming out as there are in the next 2 months).
PS3-Xbox360 gap : 1.5 millions and going up in PS3 favor !
PS3-Wii gap : 20 millions and going down !