I will base my thoughts on if the demo lives up to what they showed. The hacking seems gimmicky but it looks like they have a ton of the work done already when it comes to effects and map design so now it is probably a matter of creating missions and making the hacking abilities seem useful.

What I really liked is what I love about Assassins Creed, the city feels alive. When I hack everyones phone, people that are affected act like you might expect. Citizens are not homed in on you and treat you like an everyday NPC until you make it obvious that you are king asshole. Citizens also look like they will react to a situation like the car crash by helping other people out. Being able to to help people in the car get away from the gun fight is also kind of intriguing in that the fights are more than just kill the bad guys.

Also, the game takes place in Chicago and I recognize the city and layout as I work in Chicago. The only downside is that it isn't a perfect replica of the city (Gas Station....in the theater district? GTFO!). But the layout is accurate so that mean I know my way around the city already. I can't wait to blow up people on the Magnificent Mile =D