Kjeld,
You must keep in mind the difference between Java EE and SE. You've said that you're familiar with Java 5 (I suppose Java SE 5) and EJB3 (3.1 or 3.0?). My
test is scheduled for August 9th and I've studied the book Enterprise JavaBeans by Andrew Lee Rubinger and Bill Burke, it's an excellent book to study.
To prepare for the test I'm using the enthuware simulate, but with the question bank of the SCBCD (the old test), it's good but nowadays they already have the question bank for the new test.
Just for clarification, the certification of EJB and JPA were together and now they are split. I think that's because the EJB has reborn and surely is big enough to justify a certification for it. JPA on the other hand, was covered in the past certification test for simplicity and because of it's predecessor, the entities beans. Once it's big enough and also not bound to EJB anymore, it justify the separation.
I've used JPA with a NoSQL database (bigtable / appengine datastore), and there is also the possibility to use it outside any application server.
Some people could say that was a move from Oracle to earn more money or something like this, but I don't think so. I think it's pretty natural given the nature of both technologies. Try to see the bright side, you can study for either as you were studying for the old one. It will require a little bit more, but the reward (the knowledge), will make it worth.
Hope this help!