PC's Have Advantage over Consoles for User-Generated Content

In an interview with Gameindustry.biz, Doug Lombardi of Valve Software, suggests that PC native games are poised to fully capitalize on User-Generated Content.
“The PC has that great advantage; has had that great advantage, and it comes from multiplayer and modding starting in the early ’90s and [online] multiplayer only showing up on consoles in 2000 or 2001.”
Lombardi admits that the Playstation 3 and Xbox Live are making strides to include their fans in the development process, but platform certification will only allow gamers to distribute player to player, eliminating any commercial viability.