We've already heard the script for Star Wars: The Old Republic is more than 40 novels long. In this developer discussion, BioWare talks about the effort and why this is a game changer.
SW:TOR promises a fully voiced, more immersive MMO experience - between player and NPC, player and quest-giver, etc. The result, they hope, is a deeper investment in one's character - which of course is the coin of the realm in designing a role playing game.
The Voice of the Old Republic Featurette [Gametrailers]