The teaser trailer for Sin City is up, and it looks good. This is probably going to be the most faithful comics adaptation ever, if the intercut original art is anything to go by and the fact that it’s co-directed by Frank Miller. I recognise That Yellow Bastard as one of the source stories, and possibly Big Fat Kill and the original series. It even has the feel of the comic art- black and white with spot colours.
Update Practically the same time as I was writing the post, the trailer got taken down. Probably because there was a huge surge in traffic and it was shafting their bandwidth. There is a trailers page, you can check back later to see if the footage goes back up.