Here's the latest trailer for Shank
which not provides the first look at the co-op game play but also reveals that the game will be available on August 24th. Also included in the trailer is some new footage from the game which shows off some new levels and new weapons (specifically the shotgun).
I'm hoping there's some more cool co-op stuff that isn't shown in the trailer as I'm hoping there are some more combo moves you can pull off with a buddy. I guess we'll find out in a little more than a month.