I haven't had the chance to review all of the series that you have here, but from what I have read so far it is really helpful. I do have one question / suggesting in relation to what you are doing.
In both this ATOM article, and the previous RSS one, you indicate all of the steps to generate the XML, but I haven't seen anything in relation to getting it out of the server itself. I would think that a Web service hosted by SQL Server could address this.
Did you, or are you going to, address this aspect of SQL Server and XML?
Beer's Law: Absolutum obsoletum
"if it works it's out-of-date"