YouTube testing hybrid HTML5/Flash embeds http://bit.ly/9Gxsdr
Just another data point along the way but it does seem Flash is slowly falling out of favor. Vimeo added HTML 5 support in January and pretty much every content distribution network now has support for HTML5 as well as Flash. YouTube’s owner, Google, is one of the major HTML5 proponents.
Since launching its HTML5 player, YouTube has offered a similar viewing experience on its own site, though the convenience was not carried out to embedded videos. Instead, these linked to the clip in an Adobe Flash wrapper, which mobile devices like the iPhone and Android could identify and re-route to the source clip, but browsers without that logic built-in would see nothing at all. The new code fixes that.