http://na.aiononline.com/en/news/ope...-download.html

Edit:

According to http://www.fileplanet.com/promotions/aion/, you need to be a file planet subscriber. In that case, you're better off going to your local game store and buying the pre-order package for $5 (it counts as a $5 discount toward the actual game when you pick up the game). Of course, file planet may be hiding intentions to give away remaining keys to anyone once the paying customers have first pick. Also, with as many people as there were offering closed beta codes, it doesn't make sense that file planet is the only one with open beta codes