Reality is he is probably just updating it for newer exams. The original book was published several years ago. Of course, I have zero knowledge that that is the case, and without hearing from the author, the publisher, or someone who knows either, you probably won't get much of an answer. Telling people to wait to buy the next version hurts sales of the original version.
The real question is when will Sun update the exams (SCEA, SCBCD) to reflect EJB 3.0 and the newer specs.