Hmm i really think it will be between Wii and the 360, 360 has more milion sellers atm, and its owners do buy a lot of software.
But Wii can be around for longer, it has bigger userbase (that increases all the time), there is an increase of 3rd party support (something that was not the case in last 2 years), and games do appeal to wider audience. Plus the 360 was launched in 2005.
I think in long term Wii will have more million sellers, because of the legs.








