So far, it appears to me that Google Web API may be the only option.
Otherwise, how can one test a SOAP 1.2 compliant client library?
There is a bunch on here:
Just google for "Free WebService" or "Open WebService" and you'll find tons of open SOAP endpoints.
Remember, you can get a WSDL from any ASMX endpoint by adding ?WSDL to the url.