JAX-WS implementation bundled with JDK6 can be used to provide a web services server without any additional libraries. JVM will start with a WS server on a specified port.
https://www.oracle.com/technical-resources/articles/javase/jax-ws-2.html
http://java.sun.com/developer/technicalArticles/J2SE/jax_ws_2_pt2/
The question I have is how does this differ from project Metro? If the end goal is to host web services inside tomcat, then can I still use bundled functionality and then just redirect to this bundled ws server or is it better to deploy the metro servlet?
As far as I know JAX-WS is only a template which has to be implemented by either the JDK6 or the Metro implementation.
Metro just is the standard implementation shipped with the Glassfish Application Server. See here.
Therefore there shouldn’t be any differences.