Chromecast is already fully supported with YouTube and Netflix, two services that dominate video content on the web...
Source: http://www.phonearena.com/news/Developers-already-getting-on-board-with-Chromecast-we-catch-a-couple-smooth-alpha-demos-in-action_id45707
Source: http://www.phonearena.com/news/Developers-already-getting-on-board-with-Chromecast-we-catch-a-couple-smooth-alpha-demos-in-action_id45707