YouTube has just rolled out online video rentals similar to Amazon Unboxed. Prices for movies and TV episodes start at $0.99. and go to $3.99 for the most recent/popular movies.
So far, they don’t seem to have that many titles and their interface for browsing their catalog isn’t very good. Instead they depend on the search feature which can be easily confused with the generic search for the entire site. The ‘rental store’ probably needs some separate branding and/or color scheme.
You can find the new rental site at http://www.youtube.com/store.