Our main focus has been around allows the developer to express their policy requirements in an application, which is referred to as "intents" in the SCA Policy spec. We follow the convention of using basic string literal values to identify these requirements. At some point in the future, we may allow policySets to be expressed with an app using WS-Policy as the description. I don't see this as a requirement for 1.0, however.
In terms of jbossws-cxf supporting WS-Policy, it all depends on how that is actually configured. If it's self-contained within the WSDL itself, then there's a chance it will work. If it requires additional deployment metadata specific to JBossWS, then I can't say.