New locations? New manifestations of Xulthûl? New treasure? Aethosians? I really enjoyed this intro and you've got my mind spinning with the possibilities!
The expansion will involve the Cities, their internal conflict between the Soldiers of Light and Xulthul's cultists, and corruptors that seek to weaken the avatars. It will also provide a new victory condition: purge the cultists from all the Cities and starve Xulthul! (Well... enough to mitigate the threat it poses, anyway...)