I have some contacts who choose custom away messages, and others who have a client that automatically puts up a blank away message when they leave. However, both of these show up in my contact list as the white rectangle in front of the user icon. So I spend some time right-clicking people only to find their away message is "" (blank).
It might be nice to have an icon with or without writing on it - or a different colour - to signify when the away message has some content. Also might be nice to have a different colour for commonly-used "default" messages, so the custom ones stand out.