If you don't want to read the 20 pags of notes and want to start off the new 'story' arc, it starts in Draknor.
As for the Sorrow's Furnace area it is north of Camp Rankor. I already found a new outpost called Deldrimor War Camp (a bit north then east of Rankor). Rankor is nw of Draknor btw if you didn't know
Hope this helps folks get started with all the new stuff added to the game.
PS. Bring keys along with you (can purchase them from merchants in Draknor), as new garunteed magic item chests are strewn about. Not only are they garunteed to give you an uncommon to rare item, but each member of the group who has a key can use the chest so everyone gets a chance.... awesome stuff.