I can see some use in calling a WCF Service from SQL, but it is very limited, and they are corner cases only. Thinks like one company I know has a really archaic file based "database" system that has millions of files in it that they may not necessarily want to pull up into their newer system. They currently use a .NET app that connects to a service to get information from this legacy information, so a similar way could be done to hook the data through SQL Server for use in conjunction with SQL Server data. Like I said far fetch corner case, and I probably wouldn't go that route myself because th payload cost for the service call and resulting tabular datastream back would be to high memory wise.