In my opinion, one of the major unknowns is whether the larger userbase and lower development costs on the Wii are going to end up comming together to provide the Wii with a massively larger game library in a couple of years; if a developer put equal resources to the Wii and the PS3/XBox 360 this would translate into many more Wii games being produced than PS3/XBox 360 games (and if they devote greater resorces to the Wii this will just become a far more dramatic difference). If this happens it is likely that the "Core" gamers will own a Wii because it will have enough impressive games to justify its purchase, "General" gamers will buy a Wii because the Wii will have the largest library of games that appeal to them, and "Unconventional/New" gamers will buy the Wii because it is the only system targeted towards them; it should be noted that most "Core" gamers are probably going to own a PS3 or XBox 360, and many "General" gamers may buy one aswell.
If this happens the Wii will be in (pretty much) every household where videogames are played and could easily approach 200 Million.
