Neverwinter Nights 2: NWN 2: MotB Previews at Gamespy and Gamespot

Gamespot and Gamespy have their write ups available. Editors from both organizations attended last Thursday's event at the Obsidian offices and both articles are jam packed with information about Mask of the Betrayer.

From Gamespot:

One thing is very clear: This is very much an epic expansion. Right from the start you'll battle high-level foes such as formidable animal spirits and shadow creatures that are extremely tough to put down. The new magical spells that you can unleash are almost unbelievable in power. Correspondingly, the rewards have been jacked up considerably. It's not uncommon to reap hundreds, if not thousands, of gold pieces from a single enemy, and there's plenty of low-level magical weaponry for loot. Nevertheless, you'll need it, because the shopkeepers in Mask of the Betrayer have some truly awesome items for sale, and the sticker shock is mighty. We've encountered at least one item that cost over half a million gold pieces alone.

From Gamespy:

Adventuring in the Unapproachable East is much less about killing tons of monsters (though there's no shortage of that) than digging through the layers of subterfuge and masks that hide the truth. This is true in the storyline and is reflected in some of the beautiful new scenery that we were shown. The Rashemen city of Mulsantir will act as the "hub city" in the game, the place where much of the storyline plays out and the majority of the game's quests will be garnered. Mulsantir, like most of the other game locations, also has a dark reflection of itself on the Plane of Shadow that the players will visit. The Plane of Shadow uses a new color desaturation technique (that will be available to modders) to turn everything except the color red to black and white. In these shadowlands, certain truths are revealed so a small, benign temple of a god of healing in the "real world" is instead a huge cathedral to an evil deity. A collapsed pier in an otherwise ordinary swamp is revealed to be whole in the Plane of Shadow and it leads to the home of a group of hags called the Slumbering Coven.