I hate what DC's done to Harley Quinn ever since the New 52, and it looks like the movie is continuing the trend.
To sum up my thoughts on the trailers so far:
Don't like:
Harley Quinn both in terms of look and personality so far
Killer Croc looks atrocious
Captain Boomerang not seeming to have any boomerangs (Not to mention Jai Courtney is a TERRIBLE actor)
El Diablo's outfit
The look of the Joker
Like:
Amanda Waller
Yeah. Not looking forward to this movie. WB doesn't seem to have much of a game plan yet, and seems to be trying too hard to ape Marvel's success without understanding treating the source material with respect is a good start. They always seem to be approaching their movies with the idea of "fixing" the characters, as if the comics themselves are fundamentally flawed. I admit it worked with Batman Begins and The Dark Knight, but it hasn't worked for anything since.