I saw the third flick yesterday, good film. The music was great, and had a lot of notes that reminded me of SW. If you do go see it GET THERE EARLY. We got there just after they had started seating everyone, and it was packed.
I read the first 2 books and half of the third. Own the fourth, but not the fifth.
About movie #4, I heard that they were going to pull a "Matrix/Kill Bill" - Separate it into two parts, release part one during the summer, and part two around Labor Day. Take this as a grain of salt though.