I have found (partially) the answer to my question here:
http://forums.oracle.com/forums/thread.jspa?messageID=1724096�
///////////////////////////////
The two open source projects are independent with different goals.
TopLink Essentials is focussed on object-relational persistence addressing the reference implementation criteria of JPA as well as some advanced object-relational capabilities as determined by the TopLink Essentials community in GlassFish. Oracle plans to continue its leadership and involvement in this project.
The proposed Eclipse Java Persistence Platform project will focus on a complete persistence platform including our advanced object-relational capabilities as well as addressing object-XML, EIS, SDO, DAS, and XML-Relational.
The current plan is for these two projects to proceed independently.
Doug [Doug Clarke]
///////////////////////////////
[Message sent by forum member 'vicnov' (vicnov)]
http://forums.java.net/jive/thread.jspa?messageID=210606