regarding Saucepanman's point, I believe that the Book WK rode into Minas Tirith through the main gate as this had not been taken by an Enemy before? He could have easily flown in on his Nazgul, but wanted to be the first through the Gate so went on horseback. Maybe........
No one's mentioned Pippin in this scene. Having Gandalf on the floor we see Pippin's courage in trying to (but failing to) confront the Witch King.
Also, I know this can be seen as inconsistent, but I also think Jackson is showing that Gandalf is not all powerful or infallable. It shows that Gandalf himself seems unsure that he can beat him.
PS I agree with the point mentioned earlier on explaining the role of Merry's sword. That's one of the main reasons why I wanted the old forest / bombadil / barrow downs scenes in so he could get his Sword from Tom.
PPS Gandalf has grown since movie 1, so why not the Witch King?
PPPS Yes, Gandalf DID beat the Balrog but at what price? His Death.
PPPPS Saruman was a broken man already defeated, found out as a treasoner and therefore stripped of his powers as head of the Council before Gandalf broke his staff.
PPPPPS I'm only playing Devil's advocate here by the way.......
