Traffic shaping seems to have been vaguely successful. We're trying EXTREMELY HARD to keep our 95th percentile below 10mbit, since it appears that going beyond that will cost us incredible added monies.
Note that I don't really want to limit to the ~2mbit outgoing that's being used now -- I'm not sure why the outgoing traffic is limited so hard, and I haven't got a test domain on that box to find out. The goal is to put the dangerous customers into an "overage class" that gets a shared 10mbit, and let them fight over it -- but they should be getting 10mbit. I'm theorizing that maybe their traffic relies on high incoming bandwidth -- but I don't really know. I should be able to test once Luke wakes up.
The next thing I want to do in this area is generalize the script somewhat and make the domain creation scripts call it at boot. I'm not sure what the done thing is here -- I'm guessing making it a vif parameter would be best, then having that pass through vif-bridge and call a vif-qos script (or similar.)
Okay, I guess that's what I'll do then.