The cities in TW2 are vast. Some are not only occupying wide areas, but are also developed vertically - there's a lot of climbing possibilities, although actual free-running sequences known from Assassin's Creed are less likely. Devs promise that all (or almost all) that has doors can be opened (usually via a lockpicking minigame). Much like in TW1 you have to be well hidden, but unlike TW1 crime system isn't all-knowing. In fact, there's a subtle reputation system in place that can determine overall quests availability (but even night and day cycle can influence that particular availability) or how kindly hero's greeted in a city. Interactive AI is further complicated by the fact that (unlike in TW1) people will try to help you fight your attackers (or run scared) and there's a possibility of in-fighting between many monsters. There's been also a change to Stealth, apparently - from what the editors say, you can perform stealth attacks with many weapons (not just daggers) and animations for the kills will be varied for each weapon type.