This last bit is particularly interesting since it involves some sort of "active world PvP" outside of Cyrodiil. In a nutshell, the system allows players to murder NPCs and steal items. If caught, you can choose to pay a bounty (and lose the stolen goods) or run, exposing yourself to guards. You can also be a guard and hunt down player bounties, hence the PvP.
In terms of new zones, there are videos for Imperial City, Murkmire, and Wrothgar after the cut, as well as a look at the stealing and justice system mechanics. Dulfy has a breakdown of the panel, too, including info on new armor and weapons, spellcrafting, and more!