thanks a lot everybody
this could be a bit limiting: no matter how you play in-camera, all the Canon picture styles in my 550D (T2i) crush at least two stops of DR - on a K-5, I'd expect that to be closer to 4 (the sensor captures more DR, but the manufacturer designs the presets so that the camera delivers pretty pictures, and that means throwing away a lot of information)
you know when you shoot a still and then, when developing the RAW in the PC, you push up the curve and lots of stuff that was crushed in the shadows comes back to life? well, you can't do that in video: what's crushed in camera, is crushed forever