I came up with an interesting article, it talks on the various features included in the Sun's EJB 3.0 specification. I written-up this for java.net site. I covered most of the prominent features in EJB 3.0 (eg.,) Usage of annoatations, Interceptors, Injection, etc. But, I wrote little about the Entity Beans, which is a part of Persistence API's specification.
Specifications are organized in three categories:
i)EJB 3.0 Simplified API
ii)EJB Core Contracts and Requirements
Read the article:
What's New in EJB 3.0