During the initial Total War: Warhammer 2 announcement Creative Assembly stated that the new campaign map will be equal in size to the original, if not slightly larger. As you'll see in the full image down below, they were not joking! Total War: Warhammer 2's campaign map is just ridiculously large, both in terms of territories and the factions that inhabit them.
So if you're interested in a bit of a sneak peek at what the New World will look like, you'll find what you seek right below. The image is fairly large in size, however, so you'll have to open it in a new tab in order to get a really good look at it. Anyway, here it is:
Click the image for a bigger version
While this should be pretty much obvious to any Warhammer fan, the "??????" faction represents the ravenous hordes of the Skaven. Their full roster has not yet been revealed, but if you'd like to see some of their units in action and get a good look at their campaign storyline, you should head over here. To learn more about Total War: Warhammer 2 itself I would suggest going to the official website, though don't expect to find much about the Skaven just yet. Oh, and make sure to stay to the very end of the in-engine trailer - the Hell Pit Abomination is quite something to behold!