Interesting. But unfortunately not very useful for us; we're a SQL Server 2005 shop and Microsoft has warned in no uncertain terms that extended stored procedure support is going away. The following passage is taken from the opening page of the Database Engine Extended Stored Procedure Programming topic at MSDN Online (link):

This feature will be removed in a future version of Microsoft SQL Server. Do not use this feature in new development work (emphasis mine... SG), and modify applications that currently use this feature as soon as possible. Use CLR Integration instead.

I'd love to see this article adapted for CLR Integration using ADO function calls, which *can* be directly invoked from a CLR routine.