|GameBanshee has a preview of D&DO, along with an interview with Community Manager Victor Wachter:|
GB: What can we expect in terms of multiclassing and prestige classes when the game launches?
Victor: The game won’t have prestige classes at launch, however multiclassing is in for launch. For those not familiar with the D&D rules, this means when you gain a level in DDO you can choose to advance in different classes. So if you start your character as a Cleric and then gain a level, you could choose to advance as a fighter. Your character would then have some abilities of a Cleric and some abilities of a Fighter. Players can advance in up to three classes with one character.