Nothing to be considered as totally new, anyway, I'll post a few things here.
- The game will be totally different, IV will be much darker, grubbier, and much more detailed than the previous games.
- Niko's phone has a contact list, a camera, a text message inbox, and an organiser. The contact list is divided into City contact, Docks friend and Cab contact.
- At the end of the demo, Niko calls Roman.
- R* wants to bring visuals and gameplay to a whole new level.
- Breaking a window of a car to get in will be 'just one of the many new animations of the game'.
- While driving, the camera is placed very close behind a car.
- The reflections and damage models of cars (they drove a red Cadillac, or probably, knowing R*, a look-alike) are made very nice and realistic.
- IV will have a much better multiplayer mode than previous GTA's.
(Not sure if it's perfectly translated, I tried to do it as good as possible :p)