Well, the reason I think that NPC characters would be a good adition to the game, is because each character could be an individual, with his own stats and skills, and his own alignment settigns that might interact with yours better when you talk to him... He might be more or less prone to helping you, and there could be a loyalty meter too that goes up and down for each player with each npc they meet... This could create Amazing amounts of Diversity for players online, offline, In groups, Solo, ect...