I think that first and foremost, the acting needs a lot of work. There's a plethora of line reading going on.

The writing is bad, as there is no explanation of what is going on. I emphasize that even though it's a trailer, there still needs to be a fair amount of dialogue to move the story and introduce the characters and explain there purpose and motives.

The Joker's casting was weak. He's a tall lanky kid with a bad attempt at a "Heath Joker" makeup job. I know TDK just came out and is going to inspire people, but those who find themselves inspired should come up with their own visual take on the character.

Overall, a very sub par finish. I'm sure there was hard work put into this, but there needs to be a definitive story that's presented through BOTH dialogue and visuals. While there's some very short lines presented, there's not much dialogue at all to tell the viewer what's going on.