I've created a new prototype for the EJB 3.1 Embeddable functionality as outlined in chapter 22 of the specification. If you want to try it out, use the instructions I've provided in the article.
A final implementation for the EJB 3.1 Embeddable will be available in our Enterprise Application Platform 7 offering. This prototype will go into the JBoss Application Server 6 Community Edition. Please try it out before AS 6 goes final.