Diablo 3 - Followers Revealed, Trailer, Interviews

Blizzard has revealed a new followers system in Diablo III, with information and a trailer at the official site (thanks Zohaib for a similar link).

IGN follows (sorry) up with a preview on the topic:

Blizzard lead content designer Kevin Martens says the Followers will be active participants during your journey, often commenting on quests and environments, conversing with townsfolk and offering up hints. You can bring one Follower with you outside of towns, and each will have access to 12 skills, four of which can be active at a time. Their armor will upgrade over time and change in appearance when it does, and you can slot in rings, amulets and weapons. Each Follower will also get a distinct special item slot that lets then equip gear nobody else, including you, can.

...and FZ.se and GamePlanet have interviews (thanks Blue's):

Leonard Boyarsky: We're really excited to talk about the followers today, they really add a lot to gameplay, not only strategically, but also in really fleshing out the world as a living breathing place.

There are many aspects to them that really enliven the gameplay experience. There's a templar that's going to take a lot of damage for you, but if you're a barbarian you can choose to have him healing because you don't need someone up-front taking a lot of damage for you. If you're playing more of a ranged class, a wizard or somebody like that, you're going to use him more up-front.

We also have a scoundrel, which is the classic rogue archetype. Very humorous, very scoundrelly in his personality! He's a ranged character, and does a lot of damage such as poison multi-shots, things like that.

And we have the enchantress, she's kind of a buffing follower: she'll amplify your damage, lower enemies’ resistance and charm your enemies so they fight on your side for a while.

But basically the main thing we're getting across here is that you can pick and choose their skills as you level up and that changes their gameplay mechanics to sit better with your game style, how you're playing your character.

So there's that aspect of them but they also really bring the game world to life. When you're running around the world they comment on what's going on and comment on places in the world, and really give you a lot of background. That way you don't have to sit down and read lore books or things like that if you're not inclined to do so.