I was just surprised that the event registrar and the event executor is expected to be the very same bean, which appears strange to me. This doesn't sound like very clear design. I'd expect some logic to register an event and some other logic to execute the event when it occurs ...
However, I found in the EJB 3.1 JSR that this point is expected to be improved in EJB 3.1 (http://jcp.org/en/jsr/detail?id=318
EJB Timer Service enhancements to support cron-like scheduling, deployment-time timer creation, and stateful session bean timed objects.
Thanks anyway for your reply, Martin