Park and Watson defended the switch to HTML5 with well-worn arguments, including distrust of plug-ins on security grounds, but they also pointed out that browsers, even on the desktop, are shifting to a no-plug-in model. Although the technology was used by NBC to stream the 2008 Summer Olympics and the 2010 Winter Olympics, the network switched to Google-owned YouTube to provide the streaming infrastructure for last year's London Games.

Netflix is one of the largest licensees of Silverlight, and among the few major services that still rely on it. As the two noted, Microsoft has said it will support the Silverlight 5 browser plug-in until Oct.