Richard,
I've also been talking to Ales on IRC about this issue. He asked for a failing Arquillian test in the Weld suite. I'm including it here as it may explain better, what I'm trying to get working:
https://github.com/paulrobinson/core/blob/JAXWS_POJO_with_CDI_interceptor/tests-arquillian/src/test/java/org/jboss/weld/tests/interceptors/jaxws/InterceptorTest.java
You can run the test by:
Boot AS7.1.0.Final
git clone git@github.com:paulrobinson/core.git
cd core
git checkout JAXWS_POJO_with_CDI_interceptor
cd tests-arquillian/
mvn install -Pincontainer-remote -Dtest=org.jboss.weld.tests.interceptors.jaxws.InterceptorTest
Observe that the test fails with message:
junit.framework.AssertionFailedError: Interceptor not invoked