Up till now, the only available information is a rough translation from Spanish. However, the information accurate, being already confirmed by Obisidian’s Marketing/PR producer Matthew Rorie.
Here’s a snip of the features packed in the Storm of Zehir add-on:
– Travel the Sword Coast and Samarach using the open ended exploration of the new Overland Map. Use skills like Spot and Survival while on the Overland Map to avoid ambushes and even find hidden locales and lost artifacts.
– Create your own full party of adventurers. Devastate your foes with a squad of fireball-flinging Sorcerers, form a solid wall of steel with a party of Fighters, or strike the perfect balance in your party by spreading out the classes you choose for your characters.
– Improved party gameplay including streamlined party conversations, a new Teamwork Benefit System, and powerful party feats.
– The world’s economy reacts to your adventures and choices. And, through trading and quests, you can expand your merchant company into a massive trading empire.