We don't currently have generic EJB integration of any kind. Although we are working on integration with Seam 3.
However, you can bind ErraiService to JNDI by adding following to your ErraiService.properties:
Then you can look-up the service from your EJBs with:
ErraiService svc = new InitialContext().lookup("java:/ErraiService");
You can access the MessageBus by: svc.getBus(); and the dispatcher with: svc.getConfiguration().getRequestDispatcher();
Note: you will need to use SVN trunk to access these features. These features with be publicly released in Errai 1.1 in a few weeks.