The new areas and features coming in Diablo 3 2.4.0 have been detailed in the latest blog post.
Now opened up for exploration are Leoric’s Manor, Greyhollow Island, and beyond Sescheron’s ruins, the Eternal Woods. You can choose to raid the Mad King’s trappings for treasure, visit Greyhollow’s coastal forests, or chance it in the frozen wasteland rumored to be populated with yeti.
There will be new Set items, featuring either improved or completely new abilities.
New Set Dungeons offer new challenges with zero risks. There are rewards if you conquer these dungeons, but if you fail, your character won’t die.
If you’re loaded with cash, you can approach Orek to access the Empowered Rifts. These rifts allow you opportunities to enhance your Legendary Gems even further, but if you fail, you and your treasure are gone. It’s a gamble, but if you’re a bored veteran this might just be the challenge you’re looking for.