My friend Jesus Rodriguez has published an excellent article about one the cool features that will be part of WCF 3.5 (Orcas timeframe), "Durable Services". If you want to know more about this feature, take a look at his post here.
As part of the integration between WCF and EntLib 3.0, this last one comes with a nice feature to redirect the WCF trace to the logging application block. This is done by Entlib through a custom trace listener (system.diagnostics) that captures the trace generated by WCF, and then, transfer that trace to any of the EntLib's trace listeners (Logging application block) configured in the application.
My coleague Juan Wajnerman has written two interesting articles about "ASMX/WCF Migration" and "REST/POX". The first one describes an complete procedure to migrate a plain ASMX web service to a WCF service using an incremental approach.