This seemingly-depressing announcement is actually because Aion is switching from "shoring up" to "fixing" XP issues. On June 2nd, patch 1.9 will hit Aion's servers, and with it a host of solutions to the XP gap. The Aion community team has laid out three ways the XP will flow like rivers of honey. Wait, that would be slow and sticky. Let's go with Jell-O. In any case, 1.9 will add more quests, increased XP for quests and a new "Energy of Salvation" system that awards experience bonuses the longer you play.
So while double-experience weekends might become a scarce event in Aion, it's hopefully for the best overall. Read the letter and let us know what you think!