The Shrieking Shack maybe? I think that's Ron and Hermione in the foreground there.
The Knight Bus swerving through traffic.
A choir singing "Something wicked this way comes" throughout the trailer. Since when is there a choir at Hogwarts?
Boggart Snape walking out of the wardrobe towards Neville and the class.
Golly gee, look at our Neville (Matthew Lewis)!! And Lupin (David Thewlis) doesn't look as terrible as I expected.
This is truly a must-see! It's Boggart Snape transforming from the Riddikulus spell.
And the result! Snape (Alan Rickman) in a dress. Well...Neville's grandmother's clothes...
The Sirius poster in Hogsmeade. He's turning around and screaming (or maybe laughing?) around him.
Hermione (Emma Watson) and Ron (Rupert Grint) on the train towards Hogwarts. Obviously, the dementor has entered...
This is a cat. Yeah. A CAT!!! Is that not the creepiest cat you've ever seen? What have you done, Hermione?!?
Harry (with the Marauder's map?) and Snape (with a lit wand) in a corridor
Mr. Weasley making Harry promise not to go looking for Sirius Black in the Leaky Cauldron (to which Harry replies "Why would I go looking for someone who wants to kill me?")
Sirius pointing at someone/something in the Shrieking Shack (?)
Towards the beginning, Harry does his homework under his sheets in bed during the summer break.
Harry and Hermione running down a path
The trio staking out Hagrid's hut
Hagrid, probably during Care of Magical Creatures class, while the class runs away. Maybe he's taming a Hippogriff?
Harry doing a spell in Dumbledore's office. Maybe it's a patronus?
The hand of a Dementor opening a window on the Hogwarts Express.