This would allow you to display a status message on your profile (like on social media sites). You could post things like away messages announcing when you will be back online (after sleep, vacation, illness, etc). Your status message could also be shown to other users when they send you a message, or directly in their news feed if you are on their favorites list.
The status message should come with privacy options, allowing you decide who will see it (public, favorite users only, etc).