I just presented the Upgrade Exam for the Sun Certified Java Programmer, SE 6.0 (SAI edition). Got 47 correct questions out of 48, that's a score of 97%. I studied for two weeks using the most recent Sierra & Bates SCJP book.
I ordered two copies of the book on January 10. They haven't shipped yet. The support people said that their estimate is January 31, so I'm still waiting.
The first edition of the book is OK if you plan to take the SCJP 1.2 exam. If you're planning on taking the the SCJP 1.4 exam, you better buy the second edition.