Here is the Diablo 3 World Map. Click the map for the full image.
Caldeum
* Rivals Diablo II's Kurast in size.
* Located in Kehijstan.
* Began to decay after Kurast's nobles fled their city and took up residence in Caldeum and brought with them a sense of entitlement.
* When the unifying Emperor of Kehjistan became ill and died, the Zakarum returned and the city fell into chaos.
New Tristram
* Fell into decrepitude after the cathedral was looted.
* Now comprised of shacks and the old inn.
* Town formed by merchants looking to make a profit off of the legends of riches found in the cathedral.
* Cain says that there is still value in the cathedral in the form of ancient tomes.
Confirmed Zones: Leoric Highlands (More will be posted here soon!)
Confirmed Dungeons: Forgotten Tombs
Please post a comment below if you have discovered other maps or locations.