So you want to know more about the XML features in SQL Server 2005 do ya?
Well, you could come to one of my talks and get some of the basics. Or read some of my posts and learn a few things. You could go read lots more meaty stuff on Bob Beauchemin's Blog too. Or you could buy and read (knowledge transfer by osmosis just doesn't seem to work) Bob, Niels and Dan's outstanding “A First Look SQL Server 2005 for Developers.” Even better, you could attend one of DevelopMentor's SQL Server 2005 classes where there are not one but two modules on XML and XQuery.
However, one thing that we've really been lacking in the community is a great, comprehensive and totally free resource that gives you key facts and a technology road map. I'm pleased to say that's no longer the case.
XML Options in Microsoft SQL Server 2005 is just that.
Highly recommend reading!