OP, we refer to this form of messaging in the office as the "VPs thought of the day".. and we've resisted the active desktop idea for a while, I love BGInfo though. It just displays the machine name directly on the desktop from the logon script.
We recently purchased "Ace Messaging" (from spydaman.com) this little app hooks straight into AD, allowing you to target a building or particular group of users. The messages range from a full screen thing that even appears on top of currently running powerpoints, all the way down to little bubble messages. The best thing is it's really quick and easy to create a new message, few clicks and press send and it's done.
If the new deputy is happy to cough up for this, I'd recommend it. You pay per client install (easy to roll out via GPO) and you pay extra per user who'll be able to send messages out.
