It has been confirmed that a Greatest Hits album is going to be released on January 21, 2014. What has ALSO been confirmed is that it is NOT going to be an album of new material. Gerard did confirm this via Twitter, saying that “The release is a Greatest Hits Warner Bros. is putting out.” He also noted that he is designing the packaging for said album.
Whether or not any previously unreleased bonus tracks will appear on the as-yet-to-be-titled Greatest Hits package remains to be seen.
Brett’s note: it is a common industry practice (and nearly unheard of these days not to) to include bonus, unreleased material on retrospective albums).