Rob Jarratt has updated the community-driven WCF load test tool with a new beta release. The test tool uses a trace captured from a previous run of a WCF service to automatically generate a test case that performs the same sequence of operations. This allows you to quickly turn a hand-crafted test into one that is reproducible.
This release adds support for testing ASMX services (where a new client proxy has been generated using WCF) as well as a variety of enhancements to support additional WCF features that the tested service can include.
It seems the tool can actually be used to test any web service that a WCF client can be generated for.