I'm afraid the wiki is outdated. It refers to a prototype standalone EJB 3.1 Embeddable we created. You can find the latest version here: https://repository.jboss.org/nexus/content/groups/public/org/jboss/ejb3/jboss-ejb3-embedded/1.0.0-Alpha-2/.
In https://repository.jboss.org/nexus/content/groups/public/org/jboss/ejb3/embedded/ is the next installment we're working on. It contains both a standalone version and a paravirtualized one which runs within JBoss AS.
Currently we're working up to the M4 release of JBoss AS which should contain a preliminary version of EJB 3.1 Embeddable. Watch this space. ;)