It's not the most important feature of the ps3, but I do use it quite often. The comment bar over our gamer name. Will that be in the Ps4 in anyway shape or form? I actually update my comments more than I do my facebook statues.
I like the status bar. Just let's all of your friends what's going on in a very, very small sentence instead of sending out messages. There is only two huge down sides to it. You can't read someone when their offline and Sony needs to extend the characters limit.
From looking at pictures and videos I haven't really seen anything like it for the PS4. They just announced a few days ago our friend limit will be 2000 so maybe when they shell out a new video with more of the new XMB it'll show a glimpse of the new status bar - if there's going to be on that is.
Maybe the "About Me" section will replace it... who knows