Gamers may move in other directions, but the Wii has never been a platform for gamers. It never tried to be. Nintendo has deliberately chosen a different market than the PS3 and the Xbox. It is an interesting business case to be sure! Instead of worrying about how big their slice of the pie will be, they have opted for a bigger pie. Wiis are finding their way to nursing homes as occupational therapy for the elderly - I can't see that with a PS3!
For myself, I have never been attracted to typical video games, and have not had a game system since my Commodore 64! But Santa brought our family a Wii, and we have been having a blast playing Super Mario Galaxy. We have hardly touched Wii Sports excpet when company is over and we organize mini tournaments. I am sure that we will spend more time on it later.