Here at Comic-Con 2012, Ubisoft just unveiled a new co-op mode for Assassin's Creed III called Wolfpack. True to its name, Wolfpack sets a team of players wild on a map full of NPCs, taking out a series of targets in a race against the clock. In fact, it's that race that makes this new mode feel like an altogether unique chapter in the world of Assassin's Creed.
Wolfpack is, in a word, fast. You begin a round with a fixed amount of time, and once your team takes out its first target (or group of targets, in most cases), you get more time added to the clock. So right off the bat, there's a strong incentive to keep things moving and string your kills together as quickly as possible. It's similar to Manhunt mode, but much more focused on the rapid succession of targets.
On top of this, there's no need to be sly when taking care of your targets. The NPCs loitering around the map couldn't care less if you brutally murder someone within close proximity, so long as they don't get accidentally stabbed in the process. Just run up, kill who you need to kill, and move on. The game actually does a clever job of explaining this with a fictional snippet suggesting the Animus has been marketed as a consumer device for entertaining yourself in historical settings.
It's very easy to catch you and your teammates running totally wild in Wolfpack mode, going into a frenzy of one target assassination after another. But where this mode challenges you is in recognizing that point at which you've crossed the line from brutally efficient to downright reckless.
For one thing, you're mostly taking out groups of targets hanging out near each other. If one player rushes up and kills a target, it can spook the others and send them fleeing across the map, closing doors behind them in an attempt to escape their would-be killers (that is, you). So, the best approach is often coordinating kills with your teammates to make sure you're all perfectly in sync with one another.
Then you have situations where, instead of having you use your basic weapon, the game gives you the option to take out your targets in a more specialized manner (such as poison darts) for added points; it's the classic risk/reward scenario.
Overall, Wolfpack seems like a mode geared toward players who want to jump right into the game and have some quick and simple fun with their friends in a co-op setting. Ubisoft isn't trying to re-create the methodical pacing of the single-player game or the clever subterfuge of the competitive multiplayer mode. It's fast, it's violent, and it's its own beast.