I put this comment on http://jira.jboss.org/jira/browse/JBWS-925. I am re-posting it here as it seems appropriate to stimulate discussion on this topic.
The referenced document (http://java.sun.com/developer/technicalArticles/xml/fastinfoset) is over four years old. Since the time it was published several of your open source competitors have integrated Fast Infoset into their stacks. This includes Apache's Axis2 (http://wso2.org/library/2686) which is used by Geronimo (http://geronimo.apache.org/) and Jonas (http://jonas.objectweb.org/). It also includes Sun's reference implementation of JAX-WS (https://jax-ws.dev.java.net/) which is the basis of the Metro Web Service Stack (https://metro.dev.java.net/) used by Glassfish (https://glassfish.dev.java.net/). I don't know anything about commercial vendors, but I assume coverage is good there as well.
The reason I bring this up is because I am endeavoring to write the highest performing web service possible with open source software. Right now, we have standardized on JBoss, but the benefits of Fast Infoset look large enough that they might justify changing application servers.
Is there any possibility Fast Infoset could be integrated into the 2.0.x codebase rather than the 2.1.x codebase?