Neverwinter Nights 2: Storm of Zehir Q&A Part 1 on RPG Vault forms a party of developers to quest for details about Neverwinter Nights 2: Storm of Zehir, Obsidian's upcoming D&D RPG expansion. On answer describes the tone they are setting with the add-on, and also sets the game's release date at some point this year:

These days, sequels tend to get darker and grittier, but we've gone in the other direction with Storm of Zehir. While it certainly has some such elements, overall, it's a tale of light-hearted adventure and exploration. It's more fun and less serious. This direction for the title can be seen throughout - finding random (and not random) goodies while searching the overland map, the addition of the Swashbuckler class, the variety of personalities in the cohorts...

Storm of Zehir will be in stores before the winter holidays.