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In WCF Beta 2 however, xws_reg has been replaced by ServiceModelReg.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