It was interesting to note that 80% of 133 attendees in TSS Java symposium did not want backward compatibility of EJB 3.0 with previous releases of EJB. It was not too surprising because very few persons (popular bile blogger Hani) raised their hands during EJB 3.0 BOF that they care for backward compatibility and inter-operability of EJB 3.0 with earlier versions of EJB.
Majority attendees of TSSJS were either employee of software vendors, open source contributors, consultants or authors. Hence most of them do not have to maintain applications that use earlier versions of EJB and why do they care? Rather it's a burden on software vendors to support old APIs. Many of self-professed J2EE community leaders think backward compatibility is a deterrent for new entrants in the market space. I think it matters only for IT shops who have loads of applications using EJB 2.x APIs. Many IT shops are perfectly happy with EJB 2.x and still writing EJB 2.x applications and it will haunt them if backward compatibility is officially dropped from the EJB 3.0 specification. What does this mean to you if backward compatibility is dropped and your J2EE server vendor did not support backward compatibility with EJB 2.x ? You probably cannot run your old applications in a newer release of EJB 3.0 container and will either be forced to migrate your applications to use EJB 3.0 API or stuck with an old/unsupported application server.
If you really want backward compatibility of EJB 3.0 with EJB 2.x really I suggest you make them heard by posting your opinion on this blog or visiting http://www.theserverside.com/news/thread.tss?thread_id=32757 or sending an email to email@example.com.
Sometimes, silence is not golden!