Update - Friday September 22

Changed default positions of Dialogue, Mission Goals, and Unlock boxes.
Fixed miscellaneous preview event bugs.

Skill Updates:

Arcane Zeal: Changed the maximum amount of energy gained from 5..7 to 1..7.
Trapper’s Speed: Fixed a bug that caused this skill to decrease the time to place traps more than intended.
Spirit of Weariness: Fixed a bug that caused this spirit to remove more energy than intended.


Update - Friday September 22

Welcome to the Guild Wars Nightfall World Preview Event! This weekend, players can get a sneak peak at the new features of Guild Wars Nightfall, create Paragon and Dervish characters, use Nightfall skills, and play through a portion of the Nightfall roleplaying campaign.

All active Guild Wars accounts will automatically have access to the Preview Event. Players without a Guild Wars account can download the client from www.guildwars.com and then create a free account for the weekend by using one of the following access keys.

America: 2BBQF-MG981-PRQD7-KDM6Q-C78H3
Europe: 944NC-B1LJ4-MD6L9-718L6-1HM38

Please note that all Nightfall content and features are being presented in beta form, and are subject to change and improvement before the final release.

Campaign Overview
As a newly inducted member of the legendary Order of the Sunspears, you will be able to explore all of Istan, the great island province of the nation of Elona.
While playing in Elona, you will have the opportunity to meet and recruit Heroes into your party. Heroes are party members that follow your orders and use skills and equipment of your choosing.
During this preview event, any new characters you create in the nation of Elona are temporary and will be reset prior to the release of Guild Wars Nightfall. These beta characters cannot travel outside of Elona, cannot access account storage, and cannot sell items to traders.

Heroes
You can recruit new Heroes by completing certain quests. After recruiting a Hero, you can choose to bring him along in any mission or explorable area by adding him to your party using the party formation interface. Regardless of how many Heroes you recruit, you can invite a maximum of three Heroes into your party at any given time.
Other players in your party can also bring along Heroes. If the maximum party size of a mission is eight, you and another player can play together and each bring three Heroes.
Heroes have skills, attributes, weapons, and armor just like players do. You can use the Skills and Attributes panel to select their skills and attributes, and the Inventory panel to select their equipment. (During this preview event, you cannot yet customize your Heroes' armor.)
When a Hero is in your party, you will see a button next to that Hero's name, which you can use to bring up the Hero Control panel. Within that panel, you will see that Hero's portrait, current Health and Energy, Skill Bar, and combat mode (aggressive, defensive, passive). The Hero Control panel is an advanced interface that you don't need to use, but if you would like to change a Hero's combat mode or force him to cast a specific skill, you can do it there.
While playing the game with one or more Heroes in your party, you will also see flag buttons next to the Compass, which you can use to give them orders. To order a Hero to move to a certain spot on the map, click the flag button and then place the flag on the map. To undo that order, double-click the flag button.
Heroes don't maintain their own inventory of skills. Instead, they are able to use any skill that you have unlocked on your account.
Heroes don't maintain their own backpack or inventory of items. Instead, you can drag items from your inventory onto a Hero to equip him. Your Heroes can use weapons that you have customized for yourself.

User Interface Changes

For the duration of the World Preview Event, the game will use certain elements of the Guild Wars Nightfall user interface.
The new Skills and Attributes panel centralizes management of skills and attributes, both for player characters and Heroes. It replaces both the old Skill panel and the Attributes page from the Hero panel.
The updated Inventory panel contains a character selector, so it can be used to manage equipped weapons and armor for both player characters and Heroes.
The Compass includes new controls that allow the player to issue orders to both henchmen and Heroes.
All of these user interface changes are being presented in beta form. After the conclusion of the weekend event, they will be removed from the game again until the release of Guild Wars Nightfall.


Nightfall World Preview Event Limitations

The following features will be part of the release of Guild Wars Nightfall, but are not available during this preview event.
Skill Templates - In Nightfall, you will be able to save and load skill and attribute builds to disk, enabling you to quickly switch strategies and outfit your Heroes.
Hero Battles - After the release of Nightfall you will be able to unlock Heroes for your use with your PvP characters, and you will be able to bring Heroes into a new type of PvP where players can compete head-to-head for the first time.
Also, the following issues are known to exist with the features being previewed during this weekend event.
Hero AI for using skills is still under development.
Heroes cannot capture skills using Signet of Capture, nor can they control pets using Charm Animal.
Hero armor cannot yet be upgraded using runes.
The visual appearance of Hero armor in the Inventory panel, and the text descriptions of the Hero's attributes and items, do not take into account the sex of the Hero.
The tutorials in Prophecies and Factions have not been updated to reflect the Nightfall user interface changes.
http://www.guildwars.com/support/gameupdates/updatearchive-2006-09.php