First of all, great info on the Sectumsempra scene, via The Leaky Cauldron:
Also of note in the magazine are comments from actor Tom Felton on the infamous Sectumsempra scene in Half-Blood Prince. Tom says of the emotional confrontation between his character of Draco Malfoy and Harry Potter (Dan Radcliffe): "It was great. We spent a week in this misty bathroom set, rolling around in the water having all sorts of fights. Its a longer sequence than it is than in the book." The article continues: "There is blood-but also some fleshing out. This film develops the character further than before," he says. "We take the chance to explain why he's such a complete cretin, that he's not just doing it for the sake of doing it."
Another article on Leaky explained an extended trailer which was released at ShoWest. The details are incredible:
Cinemablend also has a longer article on the trailer. Most of what was described seems to be what we saw in the recently released trailer at the beginning of the month, with the footage of the attack on the Burrow, and the Inferi, however it does seem there was at least one new, and rather plot revealing, piece of dialogue, as they state "Dumbledore also has a line of dialogue that definitely isn't part of the book-- "Voldemort has chosen Draco Malfoy for a mission."
I am a whole new kind of excited!