In a move that has been rumored for nearly a year, MySpace users can now log in to the once dominant social network using Facebook.

At a press event this afternoon, the two companies announced an expansion of their existing partnership that puts a connect with Facebook button on the MySpace homepage and enables a wide range of personalization and sharing features on MySpace.

Through a product the companies are calling "Mashup with Facebook," users who log in with Facebook (or connect their existing MySpace account) are able to pull in their likes and interests, which makes it easy for them to do things like follow updates from their favorite entertainers. MySpace also has plans to integrate "Like" buttons across the site, meaning MySpace content like music and videos will start getting shared back to Facebook.

The move is significant for a couple reasons. First and most obvious, it's official acknowledgment on the part of MySpace that Facebook has indeed become top dog in the social networking space, and it's better to be with them than against them at this point. Second, and more important as MySpace looks to turn itself around, it creates a huge new audience for MySpace's content and affirms its focus on entertainment.

Given the role Facebook and its news feed increasingly play as a traffic source for news and entertainment websites, this has potential to boost MySpace's numbers significantly if it can also get its content strategy correct.

MySpace shows off the new features in the video below:





