I have Windows Server 2008 R2 with IIS7 on it. I deployed WCF service on it. When I specify WCF service address in browser (local or external machine) http://sbkisourcedev
The problem was with WCF identity permissions. The identity that is used for the application pool that hosts the WCF service must have full NTFS permissions on the %WINDIR%\temp folder. After changing that permission to my identity (LOCAL SERVICE) on C:\Windows\Temp I was able to add service reference to WCF service.
have you tried http://sbkisourcedev01/VCIndex/mex?