As you have all seen there has been TONS of debate about Dual Speccing and AC Speccing and some people think they are the same. Some people think that the Advanced Class is not a class but a Spec.
So here is my suggestion:
When creating the character you are instructed Select Story Arch. This would be Jedi Knight, Jedi Consular, Smuggler, Trooper, Sith Warrior, Sith Inquisitor, Imperial Agent, Bounty Hunter. Once you finish the intro zone and you go to the fleet you are then instructed to Select Your Class. Then you would pick Sith Assassin or Sith Sorcerer as an example.
I think this would help to avoid a great deal of confusion and arguing in the future.