Make WCF endpoint and other settings brain dead easy and foolproof.
Getting WCF configuration settings right is unnecessarily difficult. Fix it once and for all otherwise this hinders wider adoption of WCF.
Keith Hill commented
I wonder if WCF could benefit in some way from "convention over configuration" like ASP.NET MVC has?
Michiel Rutting commented
I find writing the actual service in WCF very easy. Nothing however ruins my day quite like having to then configure the endpoints / security / authorization for a production environment. In the end I tend to spend more time fighting with WCF settings than writing business logic.