The process has now gotten even worse. We have had to visit the Google Apps domain control panel multiple times now to disable Chat, and it some how keeps getting re-enabled. The "support" staff from Google is still clueless, after more than a dozen detailed emails showing direct XML between their XMPP system and ours.
Update from Google
We spoke to Google about this issue, apparently the Android team knows this is an issue but, well you can see:
Google: "They dont have an ETA yet, they told me they are still working on it and it will be sometime in the distant future. They cannot give an exact date or time period because there is a lot of testing and development to be done etc and all the various variables involved make it hard to give a time period. But they said they are working on it and will try to release some of the fixes in future updates to the OS. Hope that helps."
Update from Edoceo
The previous fix we listed actually does not work. Oddly what happened was that Chat/Talk got re-enabled for our domain when we told our Android phone to sync; that then caused problems for everyone else who was trying to chat with us. It’s broken and Google doesn’t care about their customers, no ETA on fix.