In addition the opening cinematic was released to go hand in hand with the reveal of the release date. You can check out the cinematic opening here.
The cinematic tells a story that sets the scene for the expansion and its time traveling extravaganza. As usual, Blizzard has done an astounding job with the cinematic. With the quality of their CG scenes, Blizzard really should consider opening a studio that makes feature films for StarCraft, Diablo, and Warcraft. Those films would do well, I guarantee it.
Hopefully the CG visuals for the Warcraft movie will be of the same caliber.