What popular well known websites use WordPress?
Microsoft migrates 30 million live space blogs to WordPress.com
High volume News / Entertainment
Techcrunch – Techcrunch, for the month of January 08, received 2.7 million + viewers to the site.
Perez Hilton – Celebrity and Entertainment Blogger and Gossiper – WordPress Website
People Magazine – Celebrity and Entertainment and Style Magazine – WordPress Website
MTV – Music | Shows| News | Movies Entertainment WordPress Website
Wall Street Journal Law Blog
General Electric reports
Volkswagen of America
Mike Row (dirty jobs)
Lance Armstrong (live strong)
WordPress is owned by a company called Automattic, more info about that here https://en.wikipedia.org/wiki/Automattic