Theater View in YouTube

YouTube displays a new option for long videos: a theater view that enlarges the player and fades out the rest of the page. Randall Munroe's talk at Google and Steve Jobs' speech at Stanford are two examples of feature length videos that should display the new option.You can restrict YouTube's search results to feature length videos by appending &longform=1:
http://www.youtube.com/results?search_query=site:youtube.com&longform=1