Using
Head First EJB you should easily obtain a SCBCD 1.3 which should ease your subsequent SCEA preparation pain considerably (as evidenced by some of the EJB related inquiries in this forum).
The SCBCD 1.3 requires detailed knowledge of a single specification
EJB 2.0. There is the
possibility of an SCBCD update (to EJB 3.0) by the end of the year. If they stick to the single specification concept that should be "no big deal", though its going to take a while for the study-guides to catch up. However Sun may be getting a bit tired of EJB being criticized and decide to add an "Designing Business Components" objective (similar to the "Designing Web Services" on the SCDJWS) where you have to determine in a scenario whether EJB is an appropriate solution and if it is, exactly what aspect is optimal. If that is the case then the next SCBCD may be somewhat harder than the current one.
However you still have the option of simply using Head First EJB as part of your SCEA preparation (through Part 1 only covers EJB 1.1; however EJB 2.0/2.1 would be handy for Part 2).