Warner Bros. and Facebook have announced a partnership offering video rentals. Apparently just in its testing phase at the moment, Warner Bros.’ blockbuster ‘The Dark Knight’ is already available for rental in the US through Facebook for 30 ‘Facebook credits’, or US$3.

The movie can be watched for 48 hours after rental download, purchasers must be logged in to their Facebook account and can post comments about the movie as they watch it. Warner Bros. will be releasing many more movies on Facebook in the near future.

“Facebook has become a daily destination for hundreds of millions of people,” Warner Bros. president of of digital distribution Thomas Gewecke says. “Making our films available through Facebook is a natural extension of our digital distribution efforts.  It gives consumers a simple, convenient way to access and enjoy our films through the world’s largest social network."

The move in to rental movies is a massive development for both Warner Bros. and Facebook, and some pundits believe it's just the start of a big move for Facebook into video services and web TV.

“A Facebook video/ web TV service does not exist at the moment but it is likely to do so in the near future and is a logical next step in the network’s growing service portfolio,” says Ovum principal analyst Enen Zoller. “Facebook is rapidly evolving beyond its core communications focus to become a wider platform for distributing and consuming entertainment services, particularly in games. At the same time, an increasing amount of online video viewing time is on social platforms, notably YouTube, but also Facebook albeit to a lesser degree.

"(The rental deal with Warner Bros. will) immediately mix the social and TV in a way that would be interactive and viral,” Zoller says, “drawing on its thriving developer community to enhance the proposition further with attractive applications. Facebook is also building a strong mobile presence and this would inevitably inform a video and web TV offer from the company."

Zoller also says the Facebook movie rental deal won’t stop with Warner Bros partnership, and Netflix might just be shaking in their boots pretty soon.

“Facebook’s large, highly engaged user base of around 600 million members will make it a very attractive distribution platform for video and TV services,” he says. “Warner Bros will be the first of many partners in this area. It will also no doubt give established online video rental and distribution platforms like Netflix cause for concern.”

What do you think? Do you want to be on Facebook when watching a movie? Are you already and would like to interact online while viewing? Is Facebook becoming too pervasive, could consumers click off? Drop a comment below.