Sending System Message scales poorly

(Bug, To be Fixed , Priority: Medium, Test Status: No automated tests yet , Reported By Justin du Coeur, )
Notifications
Summary: When I send a System Message, I am sending it individually to every User. That's a nice easy way to start, but is going to deeply suck when we have 10 million users.
Not sure what the right approach is, but it's likely that System Messages actually want to be completely separate from conventional Notifications.