"Yeah, I don't want to steal [CEO] Jack [Tretton]'s quote, but he's fond of saying: 'Microsoft owns the office; Sony owns the living room; and Wii owns the closet.' And that's an aggressive, probably quotable line."
The above is a quote from Sony Computer Entertainment America's senior vice president.
I don't know what "owning the office" means, but "owning the closet" means that Sony thinks nobody uses the Wii, and that's it's just collecting dust in the closet (as opposed to Sony's stuff owning the living room, well at least the living rooms owned by the small minority of people that has actually bought the PS3).