Hi!
The BEA Cert Developer is a cert which covers basic concepts about
JEE development (JMS, EJB, JNDI, etc) plus some WebLogic server topics.
The Architecture Cert is very harder and covers some concepts on networking and weblogic admin, and obviously JEE/BEA architecture concepts.
Im preparing for both. You can get more info and the mock exams at certification.bea.com
Daniel