zecas, you write: "So since I was going for an MDB in EJB3, I was not thinking about the need for an ejb-jar.xml on the project". Of course you weren't ! What we are doing here is fighting EJB3 tooth and nail, in order to get back to EJB2
Of course EJB2 was a terrible mess, but it did get one thing exactly right: a clean separation of "deployment" and "development" mechanisms. One aspect of deployment was the ability to configure without having to change code.
EJB3 has now melted deployment and development together to get one inflexible mechanism: "annotations". I'll tell you why I think this was done: so that inexperienced programmers who don't have a clue about what's involved can quickly write code that "runs" in a fixed environment. EJB3 creates an illusion of productivity improvement. The price you pay for this illusion is administrative nightmares.