I just saw here:
http://www.filmschoolrejects.com/news/photos-charlize-and-will-on-the-set-of-hancock.php

these two shots:
http://www.filmschoolrejects.com/images/hancock3.jpg
http://www.filmschoolrejects.com/images/hancock4.jpg

and I'm wondering what kind of camera rig is that appearing in the background.
The man is holding a black box with a lens, so it seems like a SI-2K Mini thing, where he's just holding the sensor and the lens. But then, behind Charlize Theron you can see some kind of support rig with gears and chains and part of what looks like a film mag.

Anyone with an idea of what's going on?

That is a Big Format, still photography camera... Its to big to be Mini, the SI2K mini is a just a little bigger than a cigarette package

It's a standard stills camera in a sound blimp.

It is basically a foam padded box that cuts the camera's shutter noise so that the stills photographer can take shots during scenes.