Thanks to the Youtube, you can watch the premiere online at the official Harry Potter channel (4 pm London time!)
Beware of the spoilers! (If you don't wanna know the plot twists, you shouldn't watch this!)
1. Mr. Ollivander's talking about the Elder wand.
2. Geminio spell in Gringotts Bank (clip #1).
3. Harry, Ron and Hermione after the escape from Gringotts.
4. Snape as a Headmaster asks students about Potter.
5. The Chamber of Secrets (clip #2).
6. Death Eaters trying to get in the castle.
7. Busted in the Room of Requirement.
8. Fiendfyre by Vincent Crabbe.
9. Avada Kedavra by Lord Voldemort (sneak peek).