I want to share my good news! I successfully passed the OCEJWSD6 exam with 92 %.
I used sources listed in the post OCEWSD Links for preparation:
1) Java Web Services Book: Up and Running by Martin Kalin
2) Notes Mikalai Zaikin's Free OCE WSD 6 Study Guide
Mikalai's notes were very very helpful. I prepared for the exams in just 2 weeks (might be because that I have hands on experience in developing Web Services).