No big surprise on this one. I'd definitely say that the majority of people who own PCs use them for multimedia purposes if they're not surfing the web or checking email.

"Sales of Media Center PCs have skyrocketed since July 2005, based on data from a sampling of US retailers, according to a recent study by Current Analysis. For the week ending August 20, 2005, Media Center PCs accounted for 42.60% of all desktop personal computers sold in the US retail market, up from 16.28% for the week ending July 2, 2005."