I love and hate that trailer.
I love it for being awesome, in its own right, as an awesome piece of zombie cinema.
I hate it because as its everything wrong with the Videogame Hype machine. It shows NO gameplay, doesn't hint at anything the game would eventually become, and its just a CGI piece to get fans to lay down their preorders with the blind expectations the final game would be as awesome as the trailer. It wasn't, and it didn't even come close.
For me, this is the best videogame trailer.
*Shows CGI cutscenes used in the final game.
*Hints at the gameplay with new units.
*Great previews of the story.
*The music is perfect for the trailer.
After playing Sc2 Wings of Liberty I had no interest in playing this expansion. Not because Wings of Liberty sucked, it was actually the best RTS game I've ever played (and still is). I had no interest in playing as the Zerg, my most loathed Starcraft race.
But after that trailer, I was like...
It was far better than I initially expected it to be. Never regretted my purchase. Solid recommendation.