While the Diagram component is nice it is not explicitly constrained to OrgChart behavior with custom drill-up and built-in drill-down capability like the control for the ASP.NET AJAX suite has and thus trying to implement it as such would consume too much time.  The Diagram component is amazing and certainly has valid use cases but to extend it for use as an OrgChart with all the behaviors that exist in the pure AJAX control would be a pain.