In today's Cloud Computing, SOA and Web Services, where every aspect of distributed computing can be transmitted by public and private servers using these technologies, what EJB 3.1 technologies can offer to the developers, and businesses that cannot achieved by the later.
I think it depends on what you are looking for. That is, there are numerous competing technologies but each has a unique set of advantages and disadvantages depending sometimes on the perspective of the developer. Sometimes it is not what cannot be achieved, but how well or how easily is it achieved. I think the answer depends on the specific issue of interest.