Davyd talked about integrating good old messaging systems like talk, wall, write and even WinPopup into the GNOME desktop. As it looked like a fun thing to do, I got my hands down on it today.
I still couldn't figure out how to catch wall and other pty-based messages, but I'm sure I will be able to get them working too.
At the moment, WinPopup messages work:
Maybe in-time one should be able to click the message popup and get a simple window allowing the user to reply on the incoming message, but thats to be done later on, first I want to get wall and talk requests working fine.
A little change to smb.conf is needed for this (the "message command" line should be set, I'm using a Python script to send the messages), and one file in the D-BUS system.d to allow the user Samba uses to spawn the message command ("nobody" on my system) to send messages on the system bus.
Obviously pty-based messages shouldn't need a callout anywhere.
Current code isn't ready for release yet (at all), I'll try to get what I got into good shape asap.