What I know, apart from what is written on the flyer:
there will be two trance stages; all non-trance DJs will be in the third stage, so it's possible not to notice their existence
As of today, early bird tickets at 22.50 Euros are still available. No idea of what will be the final price.
Location is Maassilo in Rotterdam, where ASOT400 was held 3 years ago.
More info: http://www.ptevents.nl/index.php?p=agenda&party=35
More than 4 months to the event, so no problem to get cheap airplane tickets for those coming from far away