That’s the place where you see new notifications, messages and friend requests and from where you can quickly access settings, your profile, help, and search. Pretty useful.
The page head is gone! As is the left-hand navigation!
And it’s not like this sort of thing is hard to do. A little “position:fixed” goes a long way. Just look at the little chat box in the lower right corner. It stays where it is regardless of where you are on the page. So should the head banner and the navigation panel.
Get on this, Facebook!