Eyal Vardi has been coding up a storm, it seems. He's got a lot of neat tools for WCF/.NET development up on his weblog.
My favorites are the WCF Debugger Visualizers. The internal structure of some of the WCF runtime objects (like ServiceHost and ServiceDescription) can get quite complicated, and spelunking those through the tiny window provided by the debugger's default property grid can be painful.
Once you install Eyal's visualizers, you get a rich visual view that makes exploring the OM much easier.
The code is up on CodePlex: WCFVisualizer