Media RSS is an RSS extension for syndicating multimedia files in RSS feeds. I just added this feature to WordPress.com video feeds, so that videos are more searchable and their feeds are more accessible in all browsers and readers.
Here is an example: http://drhailin.wordpress.com/feed/ contains the following section of code:
<enclosure url="http://hailindev.videos.wordpress.com/IBMQsAT4/video/fmt_std" length="2954752" type="video/mp4" />
<media:content url="http://hailindev.videos.wordpress.com/IBMQsAT4/video/fmt_std" fileSize="2954752" type="video/mp4" medium="video" isDefault="true" duration="29" height="300" width="400" >
<media:rating scheme="urn:mpaa">PG-13</media:rating>
<media:title type="plain">my Caption for Palace </media:title>
<media:thumbnail url="http://hailindev.videos.wordpress.com/IBMQsAT4/thumbnail/fmt_std" width="256" height="192" />
<media:player url="http://v.wordpress.com/IBMQsAT4" width="400" height="300" />
</media:content>