In WCF, you need to register the Xml Web Services with IIS.  Formerly you did that with xws_reg.exe with -v -wsat+ command line parameters.

In WCF Beta 2 however, xws_reg has been replaced by ServiceModelReg.

Just like ASP.NET, you register WCF with IIS with the -i parameter:

servicemodelreg -i

ServiceModelReg.exe can be found in the C:\WINDOWS\WinFX\v3.0\Windows Communication Foundation folder.