The Diablo 3 site has been update with a look at the new zone that will be coming with the v2.4.0 patch. Called Greyhollow Island, the adventure zone only location is outside the area where the Eternal Conflict rages and has given the team a chance to try out a special sort of narrative storytelling that doesn't get in the way of loot acquisition.
The art team also had an opportunity to flex its wings as it is a zone that has an entirely different feel from the rest of the game. Not only are the colors and ambiance different, there is also the 'creepy' factor that comes through the foliage and monsters in the area.
It became clear that to deliver the man-versus-nature feeling, it was necessary to avoid as many humanoid creatures as possible. Senior Game Designer Joe Shely explains this conscious decision in a succinct way: “Greyhollow Island is about being alone in the woods at night. It’s an untamed island filled with natural and supernatural dangers.” The monsters of the island reflect this, with natural enemies like the Primeval Hunter and Glowing Death to the more fantastical Hive Mother and Silverback.
Read the entire profile of Greyhollow Island on the Diablo 3 site.