You can and should jump directly into EJB 3. Indeed, I would never recommend anyone learn or work with EJB 2 unless they absolutely have to and I have used it since 2001/2002 myself. Although EJB 2 is a pioneering technology that brought many great ideas to the mainstream, it is really not very usable/productive compared to what is available today in terms of EJB 3, Spring and many others.
Independent Consultant — Author, EJB 3 in Action — Expert Group Member, Java EE 6 and EJB 3.1
Joined: Mar 17, 2008
Your suggestion made my voyage through EJB little bit easier. Now I can concentrate on EJB3 without fear of not having knowledge of previuos version.