Just as it looks like my buddy Erik Meijer is done with blogging (despite his short lived guest blogging stint at Lamda the Ultimate) it looks like a couple more of the folks who brought Xen to the world have started blogging. They are
William Adams: Dev Manager for the WebData XML team.
Matt Warren: Formerly a developer on the WebData XML team, now works on the C# team or on the CLR (I can never keep those straight).
Both of them were also influential in the design and implementation of the System.Xml namespace in version 1.0 of the .NET Framework.