This needs to go in jar (library) rather than the war (app)

Goes for Glassfish as well as JBoss it seems.
This sort of defies one purpose of dependency injection. You
want to be able to code alternative implementations in a library,
but have the application using that library decide deploy-time
which implementation to use.

Strangely enough this works in Tomcat 7 with Weld included in the jar.

I believe following ticket is about this issue:
https://issues.jboss.org/browse/CDI-18