Before answering your question I'll just note that the current XTS package in JBossTS already allows JaxWS clients and servers to participate in transactions using the 1.0 WSCOOR protocols. All that is need is to configure the client and server with the SOAP handlers supplied in the package. However, this WSCOOR implementation is based on a 'home-grown' soap stack embedded in the XTS implementation.
I am currently extending XTS to provide a wscoor 1.1 conformant implementation of web service transactions based on JaxWS. The WSCOOR, WSAT and WSBA 1.1 services are exposed as JaxWS endpoints. Client code will normally only access these services via a suitably configured UserTransaction or TransactionManager class but it should be possible to go 'under the hood' to configure the JaxWS layer e.g. with logging interceptors, etc.
This new XTS will rely upon on the JaxWS implementation provided by JBossWS. in App Server 5.0. However, it is not tied to the JBoss implementation, for two reasons. In AS 5.0 JBossWS is being split into a generic API layer and an implementation layer (called JBossWS-Native). This will allow alternative WS implementaions to be dropped into the AS in place of JBossWS-Native. Furthermore, the XTS implementation only relies on generic JaxWS features so it should be able to run directly over any fully compliant JaxWS 2.1 implementation, e.g. by dropping the TS and XTS implementation into a different app server.
WSCOOR 1.0 support should still be available alongside this new implementation by retaining the 'home-grown' soap stack currently embedded in the XTS package.