What we do know – which is very little – is that Aion promises this ties into the continuation of Aion‘s immortal saga, with a forum thread dedicated to discussing precisely that. Speculation is that the trailer ties into the game’s 5.0 update; a similar trailer for the game in South Korea also included a date of November 11th as a possible release date. It’s also possible that the update will include something of a makeover for the Asmodean faction. We’ll have more as more information is available; for now, there’s just a short video for speculation.
Source: Official Site