Some quick advice for anyone planning to take the exam:
1. STUDY, STUDY, STUDY - this is a difficult exam. I almost ran out of time. I program in Java every day. I studied for over 4 months for this exam. I took every practice test I could. My final score on the exam was almost identical to my practice tests average of 77%.
2. PRACTICE TEST, PRACTICE TEST, PRACTICE TEST - you cannot take enough of these. Study those areas you did poorly on when taking the practice test.
3. When taking the exam don't be lulled by your progress and time remaining. On my exam, the last 10 questions were very difficult questions about concurrency. I finished the exam with just a few minutes to spare.
4. Mark all questions you want to review for any reason. Before you submit your answers, you'll have an opportunity to review your marked questions. It's much quicker to review questions you've marked then to review questions you've not marked.
In my experience the questions in SCJP Sun Certified Programmer study guide and my practice tests WERE NOT more difficult then the exam questions. The exam questions were just as difficult and complex.