Matt Cutts, Google’s head of search spam, replies to the question – ‘Is it recommended to add schema video markup onsite in order to get your page w/embedded video to rank in SERPs in addition to the YouTube result, or is this redundant?’ in the latest webmaster video.
Matt recommended adding schema.org markup on the videos. In general, the more markup there is, it is easier for the search engines to interpret what really matters on the page. Crawling Javascript and CSS, Google figures out the context involved. If they are able to see what is going on video pre-page, they will have better idea of what is going on the site.