The official Guild Wars 2 Registration site is now setup and ready to accept codes for those who pre-ordered the game and wish to register for their 1 day headstart. (note: pre-order is different from pre-purchase).
For those who have questions about the differences between pre-order and pre-purchase, here’s a snippet from the official FAQ
A Guild Wars 2 Pre-Purchase involves buying the game in advance—that is, making full payment either through our website or through one of our authorized retailers. Those who pre-purchase Guild Wars 2 earn special benefits, including guaranteed access to our Beta Weekend Events, admittance to the game three days before release during the Headstart Access period, and the Hero’s Band, a fantastic in-game item that provides a boost to your character in everything from power to critical damage. Those who pre-purchase the game will receive a Guild Wars 2 Pre-Purchase serial code from the seller. This code provides access to all the privileges listed above. The Guild Wars 2 Pre-Purchase is offered for the Digital, Digital Deluxe, and Collector’s Editions of the game.
A Guild Wars 2 Pre-Order is a commitment to purchase Guild Wars 2 through an authorized retailer. Pre-ordering usually involves making a modest deposit. Those who pre-order Guild Wars 2 will be given a special serial code from their retailer that allows them one day of Headstart Access to the game.