A huge part of Facebook's user have no idea that Facebook filters their friends updates based on how much you interact with certain friends. Basically, on your wall you would see updates, pictures, links, and similar items from friends that you interact with the most. In my opinion, Facebook is controlling what I can and can not see and I highly dislike that. To change that
Go to "Most Recent" on your wall and click "Edit Options":
In the "Edit Your Friends Settings" drop down select "All of your friends and pages" and click " Save":
and you are done. Now you will receive updates from all your friends!