While working on the fix for Axiom, I discovered another potential issue (although I didn't see any test failures). The problem is that Spring-WS instantiates the SOAP factories (SOAP11Factory and SOAP12Factory) directly, while the recommended approach is to use OMAbstractFactory to locate the (singleton) factories. However, there is some code in Axiom that makes the assumption that factories are singletons, so this may cause problems.
It should also be noted that SOAP11Factory and SOAP12Factory are part of axiom-impl, but application code is expected to only use classes from axiom-api (and in Maven projects, axiom-impl should be a dependency with scope runtime).
I'll try to provide a patch for this issue as well.