Game Informer had an exclusive look into Crackdown to in there October 2009 issue. The story between the two games is as follows.
The infected that were inadvertently released in the first game carried a virus. This virus took over lager populations within Pacific City. The Agency started cordoning off these areas and the citizens formed a group called The Cell, and began to revolt. They didn't trust The Agency and were tired of living in fear with the infected in the sewers during the day and out in droves at night. Something like the Darkseekers in I am Legend I guess.
So now with the city in ruins, you deal with vigilante citizens trying to take back there streets from the infected and The Agency. And the infected themselves need to be eradicated. Now with a three way struggle, The Cell attacked The Agency and destroyed the agent program. Leaving the Agency with only in control of Agency Tower.
Now years later with the agent program up and running again. The Agency feels it is time to regain it's power to Pacific City.
The developers felt like they had a good basis with the structure of the city. So they fed on the players complaints. The lack of a good story. Players felt there were times in the game that you just blew things up just for that reason. Just blow it up. So now a solid narrative is being added.
There will come times in the campaign that it seems impossible for a single agent to complete mission. You will need help from a friend or two, when hordes of infected are involved.
Ruffian Games will be addressing some complaints players had of the first game. One being, in a mission you would work your way to the boss and just take them out. It was very simple and became a little repetitive. Now you're not dealing with single individuals but hordes of both The Cell and the infected. Missions will not always be directed towards them, instead you may be going after a power plant to take electricity away from The Cell organization. The Creative team wanted to have a living breathing city. For example, if you take out that power plant and afterward attack one of The Cells' camps. The Cells' guards would be fending off the infected in the dark and with there hands full you could make your way into the compound with ease.
There is a larger variety of weapons, some are a lot bigger than the previous editions. The creative staff felt that when your character progressed and gained some bulk in the first game. The weapons stayed the same and seamed almost toy like.
Don't fear that Realtime Worlds isn't involved this time around. Ruffian Games was created by people involved with the first Crackdown with the intent of getting the contract for Crackdown 2. Once they won the contract they received resumes from employees of the original team at Realtime Worlds to join Ruffian Games.
Oh yes, this one isn't just on my radar. It's in my sights.