GameSpot has a new Quake 4 Q&A, talking to Raven project lead Eric Biessman, Raven lead designer Jim Hughes, and id Software lead designer Tim Willits about the game. Questions are about the environments, squads, weapons, the singleplayer focus and the multiplayer. Here's a bit about the squads

Tim Willits: You're not a squad commander in Quake 4. You're a guy who is taking orders, not barking orders. But we wanted to make communication with your squadmates straightforward and intuitive. Basically, you'll have missions where you may have to escort or protect a VIP, meet up with your squadmates [after losing them], and so on. Different squadmates, like the tech marine and the medic, will give you armor and healing. What we really wanted to do in Quake 4 was to make your squad, which is Rhino Squad, consist of unique personalities. So, you're not just in a squad with a bunch of redshirts, you're actually part of a squad. You have these familiar guys that you'll see and interact with throughout the whole game. It really adds depth to the story and context for what you're doing and why you're doing it.