Brisban is apart of Maguuma.Not exactly, there are more connections to Brisban Wildlands atm, but i wouldn't rule out Maguuma yet. What's north for Brisban? Verdant Forest. Hopefully they will unlock that new zone. There are some new npcs added, one heading over to Brisban to check out what the bandits are doing and if you go there yourself you'll see that they are building a bridge to a place which will most likely have the entrance to Verdant. All speculation though. On another notes, it seems like the dragon after Mordremoth will be Kralk. One of those magical leylines in the cinematic went towards CD.