Blizzard is know for making excellent videos as Cinematic ones and game engine one. Unfortunatly at this moment like everything around Warcraft Movie is dim, there are no videos or trailers about actual movie so I'll put some World of warcraft cinematics and game videos made by Blizzard.

Videos

Lore 1: Coming of the Burning Legion and Scourge

Lore 2: Medivh Speaks to Thrall in a Dream

Lore 3: Medivh, The Prophet's Warning to Lordaeron

Lore 4: Arthas' Betrayal

Lore 5: Archimonde Destroys Dalaran

Lore 6: Grom Hellscream's Redemption

Lore 7: Night Elf Wisp Army Saves the World Tree

Lore 8: Illidan Returns with Naga

Lore 9: Arthas Becomes Lich King on Frozen Throne

Lore 10: Enter World of Warcraft

Lore 11: The Burning Crusade