Wow, i'm excited!
Your time spent making live action films seems to have paid off because the directing/cinematography of this trailer is well beyond that of most animations here on NG. The opening shot for example is an enigmatic and unusually proffesional rather long single shot that immediately had me engaged. The time lapse city scape, the view from under the dog, the stylish use of reflections, the frequent use of a moving camera for dynamism, it was all very nice!
The art is decent and i like the old school no bullshit detailed uncarictured charecter designs. The sort of art style popular in flashes a few years back before everyone started doing shouting, "wacky faces" and no outline blobs. I don't really like the idea of trailers in general because i like to approach a film/short with a completely blank slate (obviously impossible but, it's the target). Despite this I fully understand it's promotional value and i don't think you gave away too much with this. I've avoided reading your synposis as i want to enjoy the finished thing as much as possible.
The music was fitting and the little bit of voice acting seemed decent. The concept seems an interesting blend of the supernatural and the modern mob/gang. Overall i thought this was pretty damn great, you've obviosuly put a lot in to it and i'm excited about seeing this finished thing! Good job and good luck!