The YouTube Players team announced of implementing "Stage Video API" into the YouTube.com.
Adobe's recently launched Flash Player 10.2 beta release supports a new, more efficient video display mechanism known as "Stage Video API." The full details of how and why Stage Video speeds up video display can be found in Adobe's technical documentation.
The Players Team will be gradually experimenting with Stage Video playbacks on YouTube.com in coming weeks, but as a developer using ActionScript 3 Player APIs, you can enable Stage Video playback for your embedded video right away; simply add the wmode=direct parameter to YouTube video's URL. You'll need the Flash Player 10.2 beta installed to take advantage of the accelerated playback, but playbacks will work for users with older Flash Player versions as well.
YouTube already experimenting The Players Team knows that Stage Video for Flash playbacks is just one path to take toward improving video playback performance across the web.
HTML5's <iframe> embeds to improve video playback performance across the web.
Download: Flash Player 10.2 Beta