In addition to these characters, many have wondered how the hirelings, as know of them from Diablo II, will work in Diablo III. There was actually an interview with Leonard Boyarsky back in 2009 where he touched upon the subject. In the interview, he is asked about mercenaries returning in Diablo III. He first talks about the temporary mercenaries from the gameplay trailer as a smaller version of the followers. He then expands upon the newer version of the "Followers" as they are now known as.
Official Blizzard Quote:
We have two different types of mercenaries now. As you saw in the demo, if you got the quest where you could rescue the adventurers or their leader, those guys are a light level, where they are just along for the quest or they are just cannon fodder. You can't really control them or have anything to do with them at all.
But when you have what we are calling followers, they are the guys you can equip, give them different weapons, you can give them different armor. They will probably have some quests that involve them. Much more than in Diablo 2, you could equip them but they were more like a game mechanic in a body of an NPC. Where this time, were making them much more individuals with their own back story and their own reason for being in the world.
[There will be different types to hire but this time they will be] much more specific. They were very interchangeable in Diablo 2, they just had different skills. These ones are going to be much more geared toward certain gameplay types you'd say. Depending on how you play your class...I might be a barbarian, so I don't want another tank, I want a range or, I might want another tank.
And you will carry them with you throughout the game.
While this interview is over two years old at this point, no other information has been given about the system. Many people even believed that they will not add in this feature or that the mechanic got scrapped. With the recent announcement that all systems will be announced before the beta, the question was brought up again about these followers.
Official Blizzard Quote:
@scyberdragon Unannounced. #bashiokQuote from@Diablo What is the word on the followers system?
While I will admit that this gives us no new information on the system, it does tell us that it is still a system they have planned. When they will share it with us is still unknown however. So the big question still remains and is up for debate; In what form will these followers take? Will they have skills you can choose? How much item customization will there be? How many different types are there? Hopefully we will find out all of these answers Soon™.