Yesterday, we got all those details on Storm of Zehir, the next Neverwinter Nights 2 expansion except for one almost insignificant piece of information: a release window.

Today, publisher Atari rectified that oversight, revealing a fall release for the Obsidian-developed PC RPG expansion, which is said to harken "back to the days of the Baldur's Gate and Icewind Dale."

While the announcement did not contain any screenshots or significant new details, it was confirmed that, as previously reported, Zehir will boast a 15-hour campaign and new economic features along with new classes, spells, creatures, and playable races.

A new expansion for Obsidian Entertainment's Neverwinter Nights 2 (PC) entitled Storm of Zehir has emerged on Spanish NWN site Neverwinteros.

According to an IGN translation, the new expansion is aimed to bring Neverwinter Nights 2 back to the days of the classic PC RPGs Baldur's Gate and Icewind Dale with full party customization, dungeon crawling, and non-linear exploration of the world.

The report estimates the campaign to clock in around 15 hours in length, adding that Storm of Zehir will offer new classes, spells, creatures, and playable races. The game also features an improved economic structure which reacts to the player's exploits, allowing them to ally with trade syndicates or pirate goods on the black market.

Obsidian has since confirmed the expansion's development, but did not specify a release date for the title. Shacknews has contacted Obsidian for more information and will update when it becomes available.

Neverwinter Vault has posted a Mysteries of Westgate Q&A, asking the folks at Ossian Studios about their Atari published Neverwinter Nights 2 adventure pack.

RPG Vault has posted the first Neverwinter Nights 2: Mysteries of Westgate development diary. Alan Miranda and Luke Scull of Ossian Studios go over some of the new content found in the module, which will be published by Atari.

Over at GameBanshee they have a Mysteries of Westgate Q&A, asking Ossian Studios CEO Alan Miranda about the premium module his company is developing for Neverwinter Nights 2.

GameBanshee has posted a Neverwinter Nights 2: Mask of the Betrayer post-release Q&A, asking producer Kevin Saunders about the well received expansion pack.

WarCry's Neverwinter Nights 2 sub-site has posted the first part of an Obsidian Entertainment office visit report, going over some user made modules for Neverwinter Nights 2.

The guys at Joystiq have posted this Neverwinter Nights 2: Mask of the Betrayer Q&A. Obsidian's Nathan Davis is asked about improvements to the camera system, system performance, companion system and length of the new singleplayer campaign.

RPG Vault is where you can find the first Neverwinter Nights 2: Mask of the Betrayer development diary. This one covers the team's goals for the expansion.

RPG Vault has published the second part of their Neverwinter Nights 2: Mask of the Betrayer Q&A. Producer Kevin Saunders is asked about new henchmen, new creatures and enemies, additional spells and more.

Over at the RPG Vault you can find the first part of a Neverwinter Nights 2: Mask of the Betrayer Q&A. Producer and lead designer Kevin Saunders is asked about the improvements and new content found in the expansion pack.

GameSpot has a Neverwinter Nights 2: Mask of the Betrayer Q&A up, asking Obsidian CEO Feargus Urquhart about this upcoming expansion pack. Topics include the storyline, companions, incorporating user feedback into this expansion, and AI improvements.

GameShark has posted up a Neverwinter Nights 2: Mask of the Betrayer Q&A, asking producer Kevin Saunders about this expansion pack. Topics include the new races and sub races, the Influence system, SDK improvements, and the new campaign.

There's a Neverwinter Nights 2: Mask of the Betrayer Q&A on IGN, asking Obsidian's Feargus Urquhart about this expansion pack. Topics include storyline, continuation from the base game, new classes, additional toolset features and new monster types.

New at FiringSquad today is a Neverwinter Nights 2: Mask of the Betrayer Q&A. Obsidian lead designer Kevin Saunders is asked about the new content and features found in this expansion pack.

New at Eurogamer today is this Neverwinter Nights 2: Mask of the Betrayer interview. Obsidian Entertainment CEO Feargus Urquhart is asked about the new campaign, player death, picking new races and classes to add, designing an epic level campaign, fixing some issues from the core game, and the toolset.

There's a Neverwinter Nights 2: Mask of the Betrayer Q&A on GameSpot, asking lead designer Kevin Saunders about this upcoming expansion pack. Topics include story, the campaign, companion system changes and improved graphics.

GameBanshee is the first website with a Neverwinter Nights 2: Mask of the Betrayer Q&A, asking lead designer Kevin Saunders about the expansion pack which was announced yesterday. Saunders is asked about expansion-specific gameplay elements, the campaign, new prestige classes and sub-races, additional items and new environments.

Atari today announced that a Neverwinter Nights 2 expansion pack titled Mask of the Betrayer is on the way. Developed by Obsidian Entertainment, which also handled development of the original game, the expansion pack will feature a new campaign, as well as new feats and spells, races, monsters, weapons, items and more. Neverwinter Nights 2: Mask of the Betrayer will be released this Fall.

In Neverwinter Nights 2: Mask of the Betrayer, players are transported back to the Forgotten Realms shortly after the events detailed in the original Neverwinter Nights 2. Following the climactic battle against the King of Shadows, the player awakens alone and stranded deep beneath the earth. Surrounded by a horde of evil spirits, the player embarks on an epic adventure that reveals his true destiny. [...] "Neverwinter Nights 2: Mask of the Betrayer's engrossing campaign will conclude the storyline that began in the original Neverwinter Nights 2 and focus on combat, exploration and classic D&D dungeon-crawling," said Feargus Urquhart, CEO, Obsidian Entertainment.

According to this post on the Neverwinter Nights 2 forums, a new patch is now available for the game through the auto-updater. It offers new features and bug fixes. Thanks Blues News.