To Improve facebook timeline visibility, facebook has done some modifications on their front-look, i.e. facebook started showing timeline preview when we hover mouse on the name of any people’s or any pages.
Previously when we hover the mouse then it shows only profile picture with the total mutual friends, Add friends or Message button, but recently facebook modified it with the cover photos.
Timeline preview only show for those pages or friends who activated it previously, for others it is still showing the old layout. It is clearly indication that facebook want to attracts more and more people to self activate timeline another facebook is ready to force all of them into timeline same as facebook pages.
You are well-known that facebook has launched timeline features in the end of December. For Personal profile timeline still not compulsory, but for business pages, facebook has automatically converted on timeline on March 30th, 2012.