I'm in the end stages of doing the spec work for the various components in the System.Xml namespace I am responsible for in the Whidbey betas. After the 4th of July holidays we plan to start doing initial brain storming for what feature work we should do in Orcas/Longhorn. I thought it would be valuable to have various users of XML in the .NET Framework suggest what they'd like us to do in the Orcas version of System.Xml. What changes would people like to see? For example, I'm putting Schematron and XPathReader on the 'nice to have' list. No idea is too unconventional since this is the early brainstorming and prototyping phase.
Caveat: The fact that a technology is mentioned as being on our 'nice to have' list or is suggested in a comment to this post is not an indication that it will be implemented in future versions of the .NET Framework.