System.Data.SqlClient and System.Data.SqlServer Unification White Paper
After I "discovered" that the System.Data.SqlClient and System.Data.SqlServer namespaces are now unified, I found this white paper from Pablo Castro at Microsoft.
Managed Data Access Inside SQL Server with ADO.NET and SQLCLR
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnsql90/html/mandataaccess.asp
Guy