I don't think the Wii was really meant as a long term gaming console for 'adults'. The majority of the games are for kids and Nintendo's marketing is very colourful and simplistic (and effective), whereas the PS3 and the XBox have swathes of adult orientated games with dark and serious marketing. Nintendo have cleverly marketed it as a family console, knowing that it is parents who buy it on the pretext that they will use it too but knowing full well that eventually the kids will have taken it over - i would love to know how many wii fit boards are lying unused under beds. The same clever approach is also relevant to the controller, easy for a non gaming adult to pick up and 'have a go' and simple for their 5 year old to use. The new Sony and XBox controllers will simply allow users to have the same control functions in the more adult games on the PS3 and XBox. And how many adults do you know who own a DS or DSi ?- yet go to any airport in the summer holidays and the place is full of kids glued to their nintendos (my two youngest are addicted to theirs (as well as the Wii), yet my oldest (a mid-teen) has progressed to a PSP and an XBox and mainly for the games rather than the control inteface.
We will be Wii-ing for as long as we have wee people.
Rob