As per Joystiq:
Each campaign is going to be released as a separate disc.
Translation: It's time to fork out the cash dollars.
And here you thought there'd be no big StarCraft 2 announcement after its conspicuous absence from the BlizzCon 2008 opening ceremony. Rob Pardo, executive vice-president of game design at Blizzard announced that the campaign version of the game will be a trilogy, each part focusing on a separate race.
Terrans - Wings of Liberty
Zerg - Heart of the Swarm
Protoss - Legacy of the Void
Each campaign is going to be released as a separate disc.
Translation: It's time to fork out the cash dollars.