Since June 30, 2009, PMP Exam is based on PMBOK Guide, Fourth Edition. Many PMP aspirants are anxious to know whether there's any change in the exam pattern (such as number of questions, passing score, type of questions, difficulty level etc.) from June 30, 2009.
I specifically asked this question to PMI and their response was "No". There's no change in the exam pattern. The only difference is that the exam will be based on PMBOK Guide Fourth Edition.
If I have any updates, I'll post them on this page.