simevidas/webplatformdaily-site — pull request #19 by GeorgeTzellis (2013-06-13 10:58:12+00:00)
Title: WWWDC videos are only available to Apple developers (iOS / Mac)

This is the notice Apple shows when viewing their WWWDC videos

"Reminder: The content presented within the session videos and slides is Apple Confidential Information and is subject to the Registered Apple Developer Agreement."

So the content is restricted even more than Apple device owners, to developers.