If you look at the NPD numbers ( a service that monitors hardware and software sales), the Wii keeps clobbering the 360 and PS3 in hardware sales BUT the 360 keeps winning the software sales crown month after month. It looks like Wii owners buy the console and buy few games, while the 360 fans keep buying new titles..... Last month, the number one Wii game (which came in 4th overall) was WiiPlay, which usually wins because it comes with a controller. The first party titles usually get into the top 10 (Mario, Zelda, etc.) but you never see a Madden or Call of Duty game on the top 10 list...
My point..... Wiis are selling a lot of consoles to casual gamers, but they aren't buying a lot of titles... I hope Nintendo is making money on the consoles (PS3 and 360 hardly make anything on the consoles themselves) because the games sales are weak given the installed base out there.....