One new feature mentioned is squad AI for groups of enemies. Such squads will have an identifiable leader guiding them and will adjust to player actions, such as changing weapons. Take out the leader and a squad's tactical abilities are reduced. Boss battles will evidently also be affected by players' previous actions, though no specifics are given as to how that works. The article also notes that the dialogue system depends on a player's ability to read facial expressions and body language, the proper judgment of which will help to reveal the best response.
The game will visit five major locations, including Shanghai, Detroit and Montreal, all winding towards the formation of UNATCO, the organization served by the original Deus Ex's protagonist, JC Denton (Deus Ex 3 is a prequel, remember?). Hit the source links for more details. Hopefully, we'll start to see additional details hitting the web soon.
Source -- Eidos Forums
Source -- Hratelne.cz (Czech)