Blizzard's cinematics were always top-notch for their time. The "Black soulstone" trailer is no exception, so much detail and awesomeness - can't wait for more cinematics, hope there's plenty in D3. Leah's face is so amazingly done, didn't see such great face expressions since Half-life 2 (Valve rocks in this depertement hehe)
They put months of hard work into the Black soulstone trailer. You know the part where the wall crumbles? ... well every single rock is animated individually, to be just perfect.