Yep. They're using the web fonts service from fonts.com.
Here's a little geekier info from their web fonts FAQ
In what format is the font data transmitted for which browser?
Font data may be transmitted in EOT, WOFF, SVG or TrueType® formats. The font format that is served is dependent upon the visitor’s browser.How is the font data delivered?
Font data is deployed globally across a Content Distribution Network (CDN). When someone visits your Web font enabled Web site, the font data that you’ve licensed and implemented (using the Fonts.com Web Fonts portal) on that page will be delivered to the visitor's temporary browser cache. It will remain there until the visitor's browser session has ended, at which time it will automatically be removed from their system.